Tremolite,Campolungo, Piumogna Valley, SwitzerlandTremolite from Franklin, Sussex Co., New Jersey, United States
Tremolite is a
silicate mineral and member of the amphibole group. Chemical formula is
Ca2(Mg5.0-4.5Fe2+0.0-0.5)Si8O22(OH)2. A calcium magnesium silicate, tremolite
forms a solid-solution series with ferroactinolite, where iron substitutes in
increasing amounts for magnesium. The color of tremolite varies with increasing
iron content from colorless to white in pure tremolite to gray, gray-green,
green, dark green and nearly black in other specimens. Traces of manganese may
tint tremolite pink or violet. When well-formed, crystals are short to long
prisms. More commonly, tremolite forms unterminated bladed crystals, parallel
aggregates of bladed crystals, or radiating groups. Tremolite and actinolite
both form thin, parallel, flexible fibers up to 10 in (25 cm) in length, which
are used commercially as asbestos. Tremolite is known as nephritejade when it
is massive and fine-grained. The mineral is abundant and widespread. It is the
product of both thermal and regional metamorphism and is an indicator of
metamorphic grade because it converts to diopside at high temperatures (1,065°F/575°C
or above).
Fibrous Tremolite: one
of the six identified varieties of asbestos. About forty, 200 tons of tremolite
asbestos is mined yearly in India. it’s miles otherwise found as a contaminant.
Name: Tremolite
is derived from the Tremola Valley near St. Gothard, Switzerland. Actinolite
comes from two Greek words meaning a ray and stone, in allusion to its
frequently somewhat radiated habit.
Polymorphism &
Series: Forms a series with actinolite and ferro-actinolite
Mineral Group: Amphibole
(calcic) group: Mg=(Mg + Fe 2+) ¸ 0.90; (Na + K)A < 0.5; NaB < 0.67; (Ca
+ Na)B ¸ 1.34; Si ¸ 7.5.
Crystallography:
Monoclinic; prismatic. Crystals prismatic in habit; the prism faces make angles
of 56° and 124° with each other. The termination of the crystals is almost
always formed by the two faces of a low clinodome (Figs. 400 and 401).
Tremolite is often bladed and frequently in radiating columnar aggregates. In
some cases in silky fibers. Coarse to fine granular. Compact
TremoliteComposition: Ca2Mg5Si80 22 (0 H )2, is an end member of an isomorphous series. Iron may replace magnesium in part, and when present in amounts greater than 2 per cent, the mineral is called actinolite
TremoliteDiagnostic Features: Characterized by
slender prisms and good prismatic cleavage. Distinguished from pyroxenes by the
cleavage angle and from hornblende by lighter color.
Simple or multiple: common parallel to {100}, rarely
parallel to {001}
Optic Sign
Biaxial (-)
Birefringence
δ = 0.026
Relief
Moderate
Dispersion:
r < v weak
Occurrence of Tremolite
Tremolite is most frequently found in impure, crystalline,
dolomitic limestones where it has formed on the recrystallization of the rock
during metamorphism. It is also found in talc schists. Actinolite commonly
occurs in the crystalline schists, being often the chief constituent of
green-colored schists and greenstones. Frequently the actinolite of such rocks
has had its origin in the pyroxene contained in the igneous rock from which the
metamorphic type has been derived.
Tremolite Uses Area
The fibrous variety is used to some extent as asbestos
material. The fibrous variety of serpentine furnishes more and usually a better
grade of asbestos. The compact variety nephrite is used largely for ornamental
material by oriental peoples
Distribution
Notable localities include:
Campolungo Alp, Ticino, and Bristenstock, Uri,
Switzerland.
In the USA, from Pierrepont, Gouverneur,
Edwards, and Macomb, St. Lawrence Co., New York; at Franklin, Sussex Co., New
Jersey; and Lee, Berkshire Co., Massachusetts.
At Wilberforce, Ontario, Canada.
From Kozano, Badakhshan Province, Afghanistan.
At Lelatema, Tanzania.
In the Brumado mine, Bahia, Brazil.
References
Bonewitz, R. (2012). Rocks and minerals. 2nd ed. London: DK Publishing. Dana, J. D. (1864). Manual of Mineralogy… Wiley. Handbookofmineralogy.org. (2019). Handbook of Mineralogy. [online] Available at: http://www.handbookofmineralogy.org [Accessed 4 Mar. 2019]. Mindat.org. (2019): Mineral information, data and localities.. [online] Available at: https://www.mindat.org/ [Accessed. 2019].
Al Naslaa Rock is a unique geological formation located in the deserts of Saudi Arabia. It is renowned for its striking appearance, characterized by a massive sandstone block that appears to be split cleanly in two, almost as if by a laser or some other precise cutting tool. This remarkable natural wonder has captivated the imaginations of scientists, geologists, and tourists alike due to its mysterious and seemingly impossible formation.
Al Naslaa Rock Formation
The rock is situated in the Tayma Oasis, which is part of the Tabuk region in northwestern Saudi Arabia. It is a relatively remote and arid area surrounded by the vast expanse of desert, and it has become a popular destination for those interested in geology, archaeology, or simply intrigued by the enigmatic beauty of Al Naslaa Rock.
The most intriguing aspect of this rock formation is the perfect and seemingly symmetrical split down the center, which has led to various theories and speculations about how it came to be. Some suggest natural processes like erosion and stress fractures, while others entertain the idea of human or extraterrestrial involvement. Despite the ongoing debates, Al Naslaa Rock continues to be a subject of fascination and wonder for anyone who encounters it.
The formation of Al Naslaa Rock is a subject of geological curiosity and debate. While there is no definitive explanation for its creation, several theories have been proposed to account for this unique natural wonder. Here are some of the leading hypotheses:
Natural Geological Processes: Many geologists believe that Al Naslaa Rock’s split and its striking appearance are primarily the result of natural geological processes. One prevailing theory suggests that the rock was formed from sandstone, which is known for its layering. Over millions of years, a combination of factors like erosion, weathering, and the shifting of tectonic plates might have caused stress fractures and the eventual cleaving of the rock along its natural fault lines. This process could have resulted in the rock splitting neatly in two.
Exogenic Factors: Wind, rain, and temperature variations can contribute to the weathering of rocks. It’s possible that Al Naslaa Rock’s split was exacerbated or facilitated by these external factors over an extended period. Wind-blown sand, for example, could have acted as an abrasive agent, gradually eroding the rock along the fault lines.
Tectonic Activity: The Tayma Oasis region where Al Naslaa Rock is located is not immune to tectonic activity. It’s conceivable that movements in the Earth’s crust and the forces of compression and tension have played a role in shaping the rock, causing it to eventually split.
Alternative Theories: Some more imaginative theories have emerged, suggesting that the rock’s split might be the result of human or even extraterrestrial intervention, though these ideas lack scientific support and are generally considered highly unlikely.
What makes Al Naslaa Rock stand out are its distinctive features:
Perfect Split: The most remarkable characteristic of Al Naslaa Rock is the precision and symmetry of its split. The two halves appear as though they were cut with remarkable accuracy, which adds to the rock’s mystique.
Balanced Position: Both halves of the rock stand upright and are perfectly balanced on small pedestals, defying the laws of gravity and equilibrium.
Remote Location: Al Naslaa Rock is situated in a relatively remote desert region, making it an isolated and awe-inspiring geological formation surrounded by vast arid landscapes.
Despite ongoing scientific inquiry, the formation of Al Naslaa Rock remains an enigmatic marvel, with its origins continuing to be the subject of both fascination and debate among geologists and enthusiasts.
Split Rock Mystery of Al Naslaa Rock
Al Naslaa Rock Formation
The enigmatic split in Al Naslaa Rock is a source of fascination and mystery, as it appears to have been cleaved with remarkable precision. Numerous theories have been proposed to explain this intriguing feature, although no single theory has been definitively proven. Here are some of the leading theories:
Natural Weathering and Erosion: Many geologists believe that the split in Al Naslaa Rock is the result of natural weathering and erosion over millions of years. Sandstone, the type of rock that Al Naslaa is composed of, is known for its layering and natural fault lines. It’s possible that a combination of wind, rain, temperature fluctuations, and geological forces caused stress fractures to develop along these existing lines, ultimately leading to the rock splitting neatly in two. This theory suggests that the precision of the split is due to the pre-existing weaknesses in the rock’s structure.
Tectonic Activity: The region in which Al Naslaa Rock is located has experienced tectonic activity. Some suggest that movements in the Earth’s crust, including compression and tension forces, could have contributed to the rock’s splitting. These geological forces might have accentuated existing weaknesses in the rock’s structure.
Frost Wedging: Frost wedging is a geological process where water seeps into cracks in rocks, freezes, and expands, causing the cracks to widen and potentially lead to the splitting of rocks. In the arid desert environment where Al Naslaa Rock is located, extreme temperature variations between night and day could have contributed to frost wedging, eventually causing the rock to split.
Human or Extraterrestrial Involvement: Some more speculative theories propose that the split in Al Naslaa Rock could have been created by human or extraterrestrial intervention. Proponents of these theories point to the precision of the split and the absence of clear geological evidence as reasons to consider alternative explanations. However, these ideas lack credible scientific support and are generally considered highly unlikely.
Rapid Water Erosion: Another theory suggests that rapid water erosion, such as a sudden and intense flash flood, may have contributed to the rock’s splitting. While this might explain the clean break, it doesn’t address the precise symmetry of the split.
Despite the various theories, the exact cause of the split in Al Naslaa Rock remains a subject of ongoing geological investigation and debate. It continues to be a captivating geological mystery, drawing the attention of scientists, geologists, and curious visitors who are intrigued by the rock’s extraordinary and precise division.
Ancient Petroglyphs
Petroglyphs and rock art can be found in the vicinity of Al Naslaa Rock, adding to the historical and cultural significance of the region. These ancient carvings and paintings provide valuable insights into the people who once inhabited or visited the area. While not as well-documented as some other rock art sites, such as those in the Sahara or North America, these petroglyphs near Al Naslaa Rock are an important part of the archaeological and cultural heritage of Saudi Arabia.
Historical Significance: The petroglyphs in the region around Al Naslaa Rock are believed to date back thousands of years, possibly to prehistoric times. They serve as a tangible link to the past, offering glimpses into the lives, beliefs, and activities of ancient people who once inhabited or passed through this area.
Cultural and Religious Depictions: Many of the petroglyphs feature depictions of animals, hunting scenes, and human figures. Some may also depict religious or spiritual symbols that were significant to the cultures that created them. These carvings and paintings are valuable for understanding the cultural and religious practices of ancient societies.
Astronomical and Geometric Symbols: Some of the petroglyphs may incorporate astronomical symbols or geometric patterns. These could have been used for navigation, tracking celestial events, or as part of rituals related to the sky and cosmos. Deciphering these symbols can shed light on the knowledge and practices of ancient astronomers and mathematicians.
Communication and Storytelling: Petroglyphs often served as a form of communication and storytelling for ancient people. They could depict important events, tales of conquests, or migrations. Researchers analyze these carvings to decipher the narratives and histories of the cultures that created them.
Cultural Diversity: The diversity of petroglyphs in the region indicates that various cultures and communities have contributed to this rich tapestry of rock art over time. Studying the different styles and subjects of the petroglyphs can provide insights into the interactions and exchanges between these groups.
Conservation and Preservation: The protection and preservation of these ancient petroglyphs are of paramount importance. Vandalism and natural wear and tear pose threats to their longevity. Saudi Arabia, like many other countries with rock art sites, is working to safeguard and document these valuable historical and cultural resources.
While the exact age and cultural affiliations of the petroglyphs near Al Naslaa Rock may still be topics of research and study, they are a testament to the enduring human desire to record and communicate their experiences, beliefs, and histories through art. These ancient carvings and paintings serve as a bridge connecting the modern world with the rich heritage of those who once inhabited the deserts of Saudi Arabia.
Tourism and Conservation
Al Naslaa Rock has indeed become a tourist attraction due to its unique and enigmatic geological features. Visitors from around the world are drawn to this remote desert location in Saudi Arabia to witness the remarkable split rock formation and the surrounding desert landscape. The influx of tourists has brought both opportunities and challenges, and efforts are in place to preserve and protect the site.
Tourism at Al Naslaa Rock:
Visitor Interest: The striking appearance and mystery surrounding Al Naslaa Rock have led to a growing interest in the site. Tourists, nature enthusiasts, geologists, and photographers are among those who visit the area to witness this natural wonder.
Local Economy: The increasing popularity of Al Naslaa Rock has contributed to the local economy, as it provides opportunities for tourism-related businesses, such as tour guides, accommodations, and restaurants, to thrive in the region.
Conservation and Protection Efforts:
Access Control: To protect the site from over-tourism and potential vandalism, access to Al Naslaa Rock is often controlled. Visitors may need to obtain permits or be accompanied by authorized guides to access the area. This helps manage the number of people visiting the site and minimizes potential harm.
Educational Initiatives: Local authorities and conservation organizations often engage in educational programs to raise awareness about the importance of preserving Al Naslaa Rock and its surroundings. These programs may target both locals and tourists, emphasizing responsible and respectful behavior.
Infrastructure Development: Constructing well-maintained pathways, viewing platforms, and other visitor facilities can help reduce environmental impact by concentrating foot traffic and preventing erosion around the rock. Proper infrastructure also enhances the visitor experience.
Regulations and Enforcement: Regulations may be put in place to prohibit activities that could harm the site, such as climbing on or defacing the rock. Enforcement of these regulations is essential to discourage destructive behavior.
Monitoring and Research: Consistent monitoring and research into the geological and environmental conditions of Al Naslaa Rock and its surroundings can inform conservation efforts. Understanding how natural processes and human impact affect the site is critical for preservation.
Collaboration with Indigenous Communities: Working closely with indigenous or local communities in the area is vital. Their knowledge of the land, cultural significance, and historical context of the site can contribute to responsible management and conservation efforts.
Sustainability Initiatives: Promoting sustainable tourism practices, such as waste management and eco-friendly accommodations, can minimize the ecological footprint of visitors and contribute to long-term preservation.
Balancing tourism and conservation at Al Naslaa Rock is an ongoing challenge. While tourism can bring economic benefits to the region, it must be managed carefully to protect the geological wonder and the fragile desert ecosystem. Collaborative efforts among government authorities, local communities, and conservation organizations are essential to ensure that Al Naslaa Rock remains a natural treasure for future generations to appreciate and study.
Cultural and Mythological Significance of Al Naslaa Rock
Al Naslaa Rock holds cultural and mythological significance, particularly among indigenous peoples in the region. While it may not have a well-documented mythology like some other natural landmarks, its unique appearance and location in the desert have likely led to various local beliefs and stories. Here are some aspects of its cultural and mythological significance:
Local Folklore: In desert regions, large rock formations often feature in local folklore and legends. Al Naslaa Rock may have been the subject of such stories, passed down through generations. These stories might explain the split in the rock or attribute it to supernatural or mythological forces.
Symbolic Significance: The striking appearance of Al Naslaa Rock, with its two perfectly balanced halves, could have symbolic significance in local cultures. It might represent ideas of balance, unity, or duality, and be incorporated into rituals or ceremonies.
Possible Archaeological Significance: While not confirmed, the area around Al Naslaa Rock could have archaeological sites that hold cultural significance. These sites may contain artifacts, petroglyphs, or inscriptions that provide clues about the beliefs and practices of the ancient people who inhabited the region.
Astronomical and Navigational Uses: The rock’s unique geometry could have made it a valuable landmark for indigenous peoples for navigation or astronomical observations. It might have been used to mark certain celestial events or to guide travelers in the desert.
Cultural Identity: Al Naslaa Rock could hold cultural significance as a point of identification and pride for the local community. It may be considered a symbol of the region and its history.
Pilgrimage or Ritual Sites: There is the possibility that Al Naslaa Rock or the surrounding area was used as a site for rituals, ceremonies, or even pilgrimage by indigenous cultures. The rock’s unique features could have been seen as sacred.
Sacred Geometry: Some cultures ascribe spiritual or mystical significance to geometric patterns and shapes. The symmetry and precision of the rock’s split may have been seen as embodying sacred geometry principles.
It’s important to note that the exact cultural and mythological significance of Al Naslaa Rock may not be well-documented or widely known, and these aspects can vary among different indigenous groups or communities in the region. Further research and cultural studies could provide deeper insights into the significance of this remarkable geological formation in the local and regional context.
Scientific Research
Scientific research on Al Naslaa Rock has primarily focused on understanding its geological attributes, formation, and the unique features that make it stand out. While the exact origins of this rock formation remain a subject of debate, several scientific studies and investigations have provided valuable insights into its history. Here are some key points:
Geological Studies: Numerous geologists have conducted fieldwork and geological surveys in the vicinity of Al Naslaa Rock. They have examined the rock’s composition, its layering, and the surrounding geological context. These studies have aimed to determine the most likely natural processes that led to the rock’s split.
Dating Techniques: To estimate the age of Al Naslaa Rock and its surroundings, scientists have employed various dating techniques. Radiocarbon dating, optically stimulated luminescence (OSL), and other methods have been used to determine when certain geological events, like erosion, occurred.
Structural Analysis: The precision of the split in Al Naslaa Rock has led to in-depth structural analyses. Researchers have looked at the orientation of the rock’s bedding planes and fractures to better understand the forces that may have caused the split. They’ve also examined the symmetry and balance of the two halves.
Climate and Erosion Studies: Studies on the local climate, including temperature fluctuations, wind patterns, and precipitation, have been conducted to assess their role in weathering and erosion in the region. Researchers have explored whether rapid weathering events, like frost wedging, could have contributed to the rock’s formation.
Simulation and Modeling: Computer modeling and simulations have been used to test various hypotheses about the rock’s formation. By simulating the effects of different geological processes and forces, researchers have tried to replicate the unique features of Al Naslaa Rock.
Cultural and Historical Research: In addition to geological studies, there has been some research into the cultural and historical context of the region, which could provide insights into the indigenous peoples who may have interacted with the rock and any potential cultural or ritual significance.
It’s worth noting that scientific consensus on the formation of Al Naslaa Rock has not been fully established. The debate continues, and new research and studies may provide further insights into this intriguing geological wonder. While Al Naslaa Rock remains a geological mystery, it also serves as a testament to the curiosity and dedication of the scientific community in unraveling the secrets of the Earth’s natural history.
Comparisons with Other Geological Wonders
Al Naslaa Rock is a unique and intriguing geological wonder, but it’s not the only remarkable rock formation on our planet. Here are some comparisons between Al Naslaa Rock and other famous geological formations:
Location: Al Naslaa Rock is located in Saudi Arabia, while Uluru is in Australia’s Northern Territory.
Composition: Al Naslaa Rock is a sandstone formation, whereas Uluru is a massive sandstone monolith.
Appearance: Both formations are striking but different. Al Naslaa Rock is known for its perfect split, while Uluru is known for its massive size, rich red color, and cultural significance to the Indigenous Anangu people.
Al Naslaa Rock vs. The Wave:
Location: Al Naslaa Rock is in Saudi Arabia, whereas The Wave is found in the Vermilion Cliffs National Monument in the United States.
Formation: Al Naslaa Rock is a split sandstone formation, while The Wave is a sandstone rock feature with wave-like, undulating patterns.
Accessibility: Al Naslaa Rock is relatively remote and requires permits, while The Wave is a popular hiking destination with limited permits issued daily.
Location: Al Naslaa Rock is in the desert of Saudi Arabia, while the Giant’s Causeway is situated on the coast of Northern Ireland.
Formation: Al Naslaa Rock is a sandstone split, while the Giant’s Causeway is an area of interlocking basalt columns, formed by volcanic activity.
Geological Processes: Al Naslaa Rock’s formation is debated, with some suggesting natural weathering, while the Giant’s Causeway’s formation is well-understood and attributed to volcanic activity.
Location: Al Naslaa Rock is in Saudi Arabia’s desert, while Mount Rushmore is located in the Black Hills of South Dakota, USA.
Formation: Al Naslaa Rock is a natural sandstone formation, whereas Mount Rushmore is a sculpture carved into the granite face of a mountain.
Significance: Mount Rushmore is famous for its enormous sculpted presidential faces, representing U.S. history, whereas Al Naslaa Rock is renowned for its natural geological features.
Location: Al Naslaa Rock is in Saudi Arabia’s desert, while the Grand Canyon is a massive canyon located in the southwestern United States.
Formation: Al Naslaa Rock is a single rock formation, while the Grand Canyon is a vast geological wonder created by the Colorado River’s erosion over millions of years.
Scale: The Grand Canyon is on a much larger scale, both in terms of size and geological complexity.
These comparisons illustrate the diversity of geological wonders found around the world, each with its unique characteristics, formation processes, and cultural significance. While Al Naslaa Rock stands out for its perfect split and enigmatic origin, other formations captivate the world with their own distinct features and histories.
Visiting Al Naslaa Rock
Visiting Al Naslaa Rock can be a fascinating and unique experience, but it’s important to be prepared as the site is situated in a remote desert area in Saudi Arabia. Here’s some practical information for travelers who want to visit:
How to Get There:
Location: Al Naslaa Rock is located in the Tayma Oasis, which is part of the Tabuk region in northwestern Saudi Arabia.
Travel Restrictions: Check for current travel restrictions and visa requirements for Saudi Arabia before planning your trip. The rules and regulations can change, so it’s essential to stay updated.
Access Permit: Visitors typically require a permit to access the site. Obtain the necessary permits through local authorities or tour operators well in advance of your trip.
Local Guide: It’s advisable to hire a local guide who knows the area and can assist with navigation and interpretation of the site’s features.
What to Expect:
Remote Location: Al Naslaa Rock is in a remote desert area with little infrastructure. Be prepared for a lack of amenities like restrooms or restaurants in the immediate vicinity.
Extreme Climate: The desert climate can be extreme, with scorching temperatures during the day and cooler nights. Be sure to carry sufficient water, sunscreen, a hat, and suitable clothing for sun protection.
Sandy Terrain: The area around Al Naslaa Rock may have soft, sandy terrain. Sturdy and comfortable footwear is essential for navigating the desert landscape.
Cultural Sensitivity: Respect local customs and traditions when visiting Saudi Arabia. Dress modestly, particularly in conservative regions, and adhere to cultural norms.
Lodging: Accommodations may be limited in the immediate area. You may need to stay in nearby towns or cities and plan a day trip to Al Naslaa Rock.
Safety: Pay attention to safety guidelines provided by your local guide or authorities. Be cautious when exploring the rocky terrain to avoid falls or injury.
Photography: Al Naslaa Rock is a popular subject for photographers. Be sure to bring your camera equipment and consider the best time of day for capturing the rock’s features in optimal lighting conditions.
Preservation: Be mindful of the need to protect the site and its surroundings. Avoid climbing on or defacing the rock, and follow any specific conservation guidelines provided.
Visiting Al Naslaa Rock offers a unique opportunity to witness a geological wonder in a remote desert setting. While the journey can be challenging, the experience is well worth it for those intrigued by this remarkable split rock formation and its mysterious origins. Remember to plan your trip carefully, obtain the necessary permits, and respect the local culture and environment.
Acanthite from Freiberg dist., Erzgebirge, Saxony, GermanyAcanthite with Polybasite, Freiberg District, Erzgebirge, Saxony, Germany.Acanthite – Chispas Mine, Arizpe, Sonora, Mexico
Acanthite is a form of silver sulfide with the chemical formula: Ag2S. It crystallizes inside the monoclinic gadget and is the solid form of silver sulfide under 173 °C (343 °F). A silver sulfide, it is the maximum important ore of silver. It additionally happens in huge form and has an opaque, grayish black color. Above 350°F (177°C), silver sulfide crystallizes in the cubic machine, and it was assumed that cubic silver sulfide, known as argentite changed into a separate mineral from acanthite. it’s miles now known that they may be the identical mineral, with acanthite crystallizing within the monoclinic system at temperatures beneath 350°F (177°C). Acanthite forms in hydrothermal veins with other minerals, which includes silver, galene, pyrargyrite, and proustite. It also paperwork as a secondary alteration made from number one silver sulfides. when heated, acanthite fuses quite simply and releases sulfurous fumes. The maximum famous locality of acanthite, the Comstock Lode in Nevada, united states of america, turned into so wealthy in silver that a department of the usa mint was established at close by Carson city to coin its output.
Name: From the
Greek for thorn, in allusion to the shape of the crystals.
Polymorphism &
Series: The high-temperature cubic form (“argentite”) inverts to acanthite
at about 173 ◦C; below this temperature acanthite is the stable phase and forms
directly
Crystallography:
Isometric; hexoctahedral. Crystals most commonly show the cube, octahedron, and
dodecahedron, but are frequently distorted and arranged in branching or
reticulated groups. Most commonly massive, or as a coating.
AcanthiteComposition: Silver sulfide, Ag2S. Ag =
87.1 per cent, S = 12.9 per cent.
Diagnostic Features:
Argentite can be distinguished by its color, sectility, and high specific
gravity.
Primary
crystals rare, prismatic to long prismatic, elongated along [001], may be
tubular; massive. Commonly paramorphic after the cubic high-temperature phase
(“argentite”), of original cubic or octahedral habit
Polysynthetic on {111}, may be very complex due to
inversion; contact on {101}
Occurrence of Acanthite
Argentite is an critical primary silver mineral found in
veins related to local silver, the ruby silvers, polybasite, stephanite,
galena, and sphalerite. it could also be of secondary starting place. it’s
miles located in microscopic inclusions in so-called argentiferous galena.
Argentite is an important ore in the silver mines of Guanajuato and some place
else in Mexico; in Peru, Chile, and Bolivia. vital ecu localities for its
prevalence are Freiberg in Saxony, Joachimsthal in Bohemia, Schemnitz and
Kremnitz in Czechoslovakia, Kongsberg in Norway. in the united states of
america it’s been an important ore mineral in Nevada, appreciably on the
Comstock Lode and at Tonopah. it’s also found in the silver districts of
Colorado, and in Montana at Butte related to copper ores.
Acanthite Uses Area
An important ore of silver
This mineral has aesthetic price and is precious
because of its shortage.
it may be an effective manner of decreasing
steel availability and toxicity in infected soils.
• Bonewitz, R. (2012). Rocks and minerals. 2nd ed. London: DK Publishing. • Dana, J. D. (1864). Manual of Mineralogy… Wiley. • Handbookofmineralogy.org. (2019). Handbook of Mineralogy. [online] Available at: http://www.handbookofmineralogy.org [Accessed 4 Mar. 2019]. • Mindat.org. (2019): Mineral information, data and localities.. [online] Available at: https://www.mindat.org/ [Accessed. 2019]. • Smith.edu. (2019). Geosciences | Smith College. [online] Available at: https://www.smith.edu/academics/geosciences [Accessed 15 Mar. 2019].
Chromite is an oxide mineral that an ironchromium oxide with formula: FeCr2O4. It is belonging to the spinel group. Chromite is the most important ore of chromium. Crystals are uncommon, but when found they are octahedral. Chromite is usually massive or in the form of lenses and tabular bodies, or it may be disseminated as granules. It is sometimes found as a crystalline inclusion in diamond. Chromite is dark brown to black in color and can contain some magnesium and aluminum. Chromite is most commonly found as an accessory mineral in iron- and magnesium-rich igneous rocks or concentrated in sediments derived from them. It occurs as layers in a few igneous rocks that are especially rich in iron and magnesium. Almost pure chromite is found in similar layers in sedimentary rocks. The layers are preserved when the sedimentary rocks metamorphose to form serpentinite. Referred to as chromitites, these rocks are the most important ores of chromium. The weathering of chromite ore bodies can also lead to its concentration in placer deposits.
Polymorphism &
Series: Forms series with magnesiochromite and hercynite.
ChromiteComposition: FeCr20 4. FeO = 32.0 per
cent, Cr20 3 = 68.0 per cent. The iron may be replaced by magnesium, and the
chromium by aluminum and ferric iron.
Diagnostic Features:
The submetallic luster usually distinguishes chromite, but the green borax bead
is diagnostic
Mineral Group: Spinel
group.
Crystallography:
Isometric; hexoctahedral. Habit octahedral. Crystals small and rare. Commonly
massive, granular to compact.
Environment: In
metamorphic Serpentine deposits, and also in ultrabasic igneous rocks, and in
placer deposits. May also occur in meteorites.
A cumulus mineral in ultramafic portions of layered mafic
igneous rocks; an accessory mineral in alpine-type peridotites; also detrital.
Common in all meteorites, except carbonaceous chondrites, and in lunar mare
basalts.
Chromite is a common constituent of peridotite rocks and the
serpentines derived from them. One of the first minerals to separate from a
cooling magma; large chromite ore deposits are thought to have been derived by
such magmatic differentiation.
The important countries for its production are New
Caledonia, Southern Rhodesia, Greece, U.S.S.R., and Canada. Found only
sparingly in the United States. Pennsylvania, Maryland, North Carolina, and
Wyoming have produced it in the past. California is the only important
producing state at present (1940). Also found in the Philippine Islands.
Chromite Uses Area
The only ore of chromium. Chromium is used with various other
metals to give hardness to steel, also as a plating material because of its
non-corrosive nature. Chromite bricks are used to a considerable extent as
linings for metallurgical furnaces, because of their neutral and refractory
character. The bricks are usually made of crude chromite and coal tar but
sometimes of chromite with kaolin, bauxite, or other materials. Chromium is a
constituent of certain green, yellow, orange, and red pigments and of similarly
colored dyes.
Distribution
Widespread. From Gassin, Var, France.
Large crystals from Hangha, Sierra Leone.
At Tiebaghi, New Caledonia.
As economic deposits in: the Bushveld complex,
Transvaal, South Africa.
From the Great Dyke, Zimbabwe.
From many localities in Turkey.
At Saranay and elsewhere in the Ural Mountains,
Russia.
• Bonewitz, R. (2012). Rocks and minerals. 2nd ed. London: DK Publishing. • Dana, J. D. (1864). Manual of Mineralogy… Wiley. • Handbookofmineralogy.org. (2019). Handbook of Mineralogy. [online] Available at: http://www.handbookofmineralogy.org [Accessed 4 Mar. 2019]. • Mindat.org. (2019): Mineral information, data and localities.. [online] Available at: https://www.mindat.org/ [Accessed. 2019].
“Alma King”, largest known rhodochrosite crystal, Denver Museum of Nature and ScienceRhodochrosite with Fluorite,Tetrahedrite, QuartzRhodochrosite, from the Sweet Home Mine, Colorado, private collection
Rhodochrosite is a carbonate mineral with formula: MnCO3. It has a classic rose-pink color, but specimens can also be brown or gray. It forms dogtooth or rhombohedral crystals like calcite, but it may also occur in stalactitic, granular, nodular, botryoidal, and massive habits. Rhodochrosite is found in hydrothermal ore veins with sphalerite, galena, fluorite, and manganese oxides. It also occurs in metamorphic deposits and as a secondary mineral in sedimentary manganese deposits. Abundant at Butte, Montana, and other localities, rhodochrosite is sometimes mined as an ore of manganese.
Name: Derived
from two Greek words meaning rose and color, in allusion to its rose-pink
color.
Polymorphism &
Series: Forms two series, with calcite and with siderite.
Mineral Group: Calcite
group.
RhodochrositeComposition: Manganese carbonate,
MnC03. MnO = 61.7 percent, C02 = 38.3 percent. Iron is usually present,
replacing a part of the manganese, and some analyses report calcium, magnesium,
zinc.
Diagnostic Features:
Told usually by its pink color, rhombohedral cleavage, and hardness (4).
Distinguished by its hardness from rhodonite (MnSi03, H. = 5, 5-6, 5).
Crystallography:
Rhombohedral; scalenohedral. Only rarely in crystals of the unit rhombohedron;
frequently with curved faces. Usually cleavable massive; granular to compact.
Environment: Hydrothermal
veins associated with Silver, Copper, and lead sulfides; may also be found in
some pegmatites.
Pink,
rose, red, yellowish-grey, brown, white, gray; colourless to pale rose in
transmitted light.
Streak
White
Luster
Vitreous,
Pearly
Cleavage
Perfect
On {1011}.
Diaphaneity
Transparent, Translucent
Mohs Hardness
3,4 – 4
Crystal System
Trigonal
Tenacity
Brittle
Density
3.7 g/cm3 (Measured) 3.7 g/cm3 (Calculated)
Fracture
Irregular/Uneven, Conchoidal
Parting
On {0112} at times.
Crystal habit
Rhombohedral and scalenohedral crystals; also
commonly bladed, columnar, stalactitic, botryoidal, granular or massive
Rhodochrosite Optical Properties
Color / Pleochroism
Weak
RI
values:
nω = 1.814 – 1.816 nε = 1.596 – 1.598
Twinning
On {1012} as contact and lamellar
Optic Sign
Uniaxial (-)
Birefringence
δ = 0.218
Relief
High
Occurrence of Rhodochrosite
A primary mineral in low- to moderate-temperature
hydrothermal veins; in metamorphic deposits; common in carbonatites; authigenic
and secondary in sediments; uncommon in granite pegmatites.
Rhodochrosite is a comparatively rare mineral, occurring in
veins with ores of silver, lead, and copper, and with other manganese minerals.
Rhodochrosite Uses Area
Its primary use is as ore of manganese, which is
a key part of minimal effort treated steel definitions and certain aluminum
amalgams.
Quality banded examples are frequently utilized
for decorative stones and jewelry. Because of its being moderately delicate,
and having flawless cleavage, it is exceptionally hard to cut, and along these
lines seldom discovered faceted in gems.
Manganese carbonate is incredibly ruinous to the
amalgamation procedure utilized in the convergence of silver minerals, and were
frequently disposed of on the mine dump.
Distribution
Numerous localities; only a few for fine specimens are
listed.
From Cavnic (Kapnikbanya) and Herja (Kisbanya),
Baia Mare (Nagyb´anya) district, Romania.
In the Wolf mine, near Herdorf, Westphalia,
Germany.
In Russia, from the Vuoriyarvi carbonatite
complex and the Kovdor massif, Kola Peninsula.
Large twinned crystals at Mont Saint-Hilaire,
Quebec, Canada.
In the USA, from the Emma mine, Butte, Silver
Bow Co., Montana; in Colorado, at many localities, as fine large crystals in
the Home Sweet Home mine, Alma, Park Co., from the Climax mine, Lake Co., in
the Sunnyside mine, near Silverton, San Juan Co., and the Mountain Monarch
mine, Ouray Co.
In Mexico, from Cananea, Sonora, and Santa
Eulalia, Chihuahua. Large crystals from the Huallapon mine, Pasto Bueno, Ancash
Department, and in the Uchuc-Chacua deposit, Cajatambo Province, Peru.
In Province, Peru.
A large deposit of ornamental banded material at
the Capillitas mine, San Luis, Catamarca Province, Argentina.
Exceptional crystals from the Hotazel and
N’Chwaning mines, near Kuruman, Cape Province, South Africa.
From the Inakuraishi and Yakumo mines, Hokkaido,
Japan.
References
Bonewitz, R. (2012). Rocks and minerals. 2nd ed.
London: DK Publishing.
Dana, J. D. (1864). Manual of Mineralogy… Wiley.
Handbookofmineralogy.org.
(2019). Handbook of Mineralogy. [online] Available at:
http://www.handbookofmineralogy.org [Accessed 4 Mar. 2019].
Mindat.org.
(2019): Mineral information, data and localities.. [online] Available at:
https://www.mindat.org/ [Accessed. 2019].
Alteration refers to a change in the physical or chemical properties of rocks and minerals. In geology, alteration is a common term used to describe the transformation of rocks and minerals due to various geological processes, such as weathering, metamorphism, and hydrothermal activity.
For example, hydrothermal alteration occurs when hot, mineral-rich fluids interact with rocks and minerals, causing them to change in terms of their mineral composition, texture, and structure. The alteration of rocks and minerals can result in the formation of new minerals, and in some cases, the concentration of valuable minerals such as gold and silver.
In general, understanding the extent and nature of alteration is important for mineral exploration and mining, as it provides information about the location and type of minerals present in an area, and can help geologists and miners target areas for exploration and extraction.
Hydrothermal alteration zones associated with porphyry copper deposit
Hydrothermal alteration is a geological process that occurs when hot, mineral-rich fluids interact with rocks and minerals, changing their physical and chemical properties. This interaction can lead to the formation of new minerals and the alteration of existing minerals, which can result in the formation of mineral deposits, including those containing metals such as copper, gold, and silver.
Hydrothermal alteration can occur in a variety of geological settings, such as volcanic environments, hot springs, and geothermal systems. The fluids involved in hydrothermal alteration can be derived from magma or other deep sources, and can carry dissolved metals and minerals as they move through the Earth’s crust.
The extent and nature of hydrothermal alteration are important for mineral exploration and mining, as they provide valuable information about the location and type of minerals present in an area. By understanding the geological processes that led to the formation of mineral deposits, geologists and miners can better target areas for exploration and extraction.
Importance of Hydrothermal Alteration and Mineral Exploration
Hydrothermal alteration is important in mineral exploration and mining because it can provide valuable information about the location and type of minerals present in an area. By understanding the geological processes that led to the formation of mineral deposits, geologists and miners can better target areas for exploration and extraction.
For example, hydrothermal alteration can result in the formation of new minerals and the concentration of valuable minerals such as gold and silver. The extent and nature of hydrothermal alteration can indicate the presence of mineral deposits, and can provide information about the mineralization process and the conditions that existed at the time of mineral formation.
In addition, hydrothermal alteration can also affect the physical and chemical properties of rocks and minerals, making them easier or more difficult to extract. By understanding the extent and nature of alteration, miners can develop more effective extraction methods and minimize the impact of mining on the environment.
In summary, the importance of hydrothermal alteration in mineral exploration and mining lies in its ability to provide valuable information about the location, type, and characteristics of mineral deposits, and to inform effective exploration and extraction strategies.
Indication of size/intensity of system, may equate to potential The areal extent of the alteration can vary considerably, sometimes being limited to a few centimeters on either side of a vein, at other times forming a thick halo around an orebody
Controls of Alteration
There are several factors that control the extent and nature of hydrothermal alteration. Some of the key controls include:
Temperature: The temperature of the hydrothermal fluids plays a major role in determining the extent and nature of alteration. Higher temperatures result in more intense alteration, while lower temperatures result in less intense alteration.
Fluid Composition: The composition of the hydrothermal fluids can also influence the extent and nature of alteration. Different minerals will form depending on the composition of the fluids, so it is important to understand the composition of the fluids in order to predict the nature of the alteration.
Pressure: The pressure of the hydrothermal fluids can affect the extent and nature of alteration. Higher pressures can result in more intense alteration, while lower pressures can result in less intense alteration.
Fluid Flow: The flow of hydrothermal fluids through the rock is another important factor that controls the extent and nature of alteration. Faster fluid flow can result in more intense alteration, while slower fluid flow can result in less intense alteration.
Host Rock: The type of host rock can also affect the extent and nature of alteration. Different types of rocks can have different permeabilities, and the permeability of the rock will influence the rate and extent of fluid flow and therefore the nature of the alteration.
Time: The duration of hydrothermal fluid flow can also play a role in the extent and nature of alteration. Over time, more intense alteration can occur if the fluid flow is sustained.
By understanding the controls of hydrothermal alteration, geologists and miners can better predict the extent and nature of alteration, and therefore the location and type of mineral deposits.
Alteration intensity
Alteration intensity refers to the degree to which the host rock has been changed by hydrothermal fluid interactions. It is a measure of the extent of mineral replacement, mineral growth, and mineral dissolution that has occurred within the rock. High alteration intensity indicates a more extensive alteration event, while low alteration intensity suggests a more limited or shallow alteration event. The intensity of alteration can be an important factor in determining the potential for mineralization and the type of deposit that may have formed. In mineral exploration, the alteration intensity is usually evaluated based on the abundance and distribution of alteration minerals, the degree of homogenization or zoning within the altered rock, and the overall volume of altered rock compared to unaltered rock. The intensity of alteration can also vary within a single hydrothermal system, with some parts of the system experiencing higher alteration intensity than others.
Types of alterations
There are several types of hydrothermal alteration that can occur in geological systems, including:
Propylitic alteration: characterized by the formation of minerals such as chlorite, epidote, and sericite.
Phyllic alteration: characterized by the formation of minerals such as muscovite, kaolinite, and sericite.
Argillic alteration: characterized by the formation of minerals such as kaolinite, halloysite, and dickite.
Silicic alteration: characterized by the formation of minerals such as quartz, silica, and chalcedony.
Advanced argillic alteration: characterized by the formation of minerals such as pyrophyllite, diaspore, and kaolinite.
Potassic alteration: characterized by the formation of minerals such as K-feldspar and biotite.
Sodic alteration: characterized by the formation of minerals such as albite and nepheline.
The specific type of alteration that occurs can be influenced by a number of factors, including the chemical composition of the fluid, the temperature and pressure conditions, the host rock composition, and the duration and intensity of the fluid-rock interaction. Understanding the type of alteration that has occurred can be important in mineral exploration as it can provide clues as to the nature of the hydrothermal system and the type of mineralization that may be present.
Propylitic alteration
A: Propylitic alteration in host rocks adjacent to the ore body, and B: Surface exposure of argillic alteration at Sarab-3 deposit (view to to the north)Mineralogy and electron microprobe studies of magnetite in the Sarab-3 iron Ore deposit, southwest of the Shahrak mining region (east Takab) – Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/A-Propylitic-alteration-in-host-rocks-adjacent-to-the-ore-body-and-B-Surface-exposure_fig1_329865470 [accessed 31 Mar, 2023]
Propylitic alteration is a type of hydrothermal alteration that occurs in volcanic and plutonic rocks. It is characterized by the alteration of primary minerals, such as feldspar and quartz, to secondary minerals, such as chlorite, epidote, and sericite. Propylitic alteration typically occurs at lower temperatures (less than 200°C) and involves the introduction of hydrogen ions and other elements into the rock. This type of alteration is often associated with the formation of copper and gold deposits and is an important indicator of potential mineralization. In mineral exploration, propylitic alteration can be used as a guide to help identify areas with a higher likelihood of hosting mineral deposits.
Phyllic alteration
(A) Phyllic-altered granite (Smoky); (B) Microclinized granite (Salame) showing the association between potassium feldspar crystals and milky quartz grains. Araujo Castro Lopes, Adriana & Moura, Márcia. (2019). The Tocantinzinho Paleoproterozoic Porphyry-Style Gold Deposit, Tapajós Mineral Province (Brazil): Geology, Petrology and Fluid Inclusion Evidence for Ore-Forming Processes. Minerals. 9. 29. 10.3390/min9010029.
Phyllic alteration is a type of hydrothermal alteration that occurs at higher temperatures (typically between 200°C and 400°C) and is characterized by the alteration of primary minerals to secondary minerals such as muscovite, kaolinite, and sericite. Unlike propylitic alteration, phyllic alteration typically involves the removal of most of the original primary minerals and their replacement by secondary minerals. This type of alteration is often associated with the formation of porphyry copper and gold deposits and is an important indicator of potential mineralization. In mineral exploration, phyllic alteration can be used as a guide to help identify areas with a higher likelihood of hosting mineral deposits.
Argillic alteration
Argillic zone alteration from hydrothermal veins (Orphan Boy Mine, Butte, Montana, USA) James St. John (flickr.com)
Argillic alteration is a type of hydrothermal alteration that occurs at even higher temperatures (typically greater than 400°C) and is characterized by the formation of clay minerals, such as illite and kaolinite, from the alteration of primary minerals such as feldspar and quartz. Argillic alteration typically occurs in the upper levels of a hydrothermal system, above the zone of phyllic alteration, and is often associated with porphyry copper and gold deposits. In addition to the formation of clay minerals, argillic alteration may also result in the formation of silica minerals, such as quartz and chalcedony, and the enrichment of certain elements, such as gold, silver, and molybdenum. The presence of argillic alteration is an important indicator of the potential for mineralization, and is often used in mineral exploration to help identify areas with a higher likelihood of hosting mineral deposits.
Silicic alteration
Photomicrographs of (a & b) Silicic alteration, (c & d) Sericite-illite alteration zone, (e & f) Propylitic alteration zone. Abbreviations: calcite (Cal), quartz (Qtz), adularia (Adl), sericite (Ser), illite (Ilt), epidote (Epi), chlorite (Chl) and opaque mineral (Opq).
Tay Zar, Aung & Warmada, Iwayan & Setijadji, Lucas & Watanabe, Koichiro. (2017). Geochemical Characteristics of Metamorphic Rock-Hosted Gold Deposit At Onzon-Kanbani Area, Central Myanmar. Journal of Geoscience, Engineering, Environment, and Technology. 2. 191. 10.24273/jgeet.2017.2.3.410.
Silicic alteration is a type of hydrothermal alteration that results in the formation of silica minerals, such as quartz and chalcedony. It occurs at even higher temperatures (typically greater than 500°C) than argillic alteration and is typically found in the uppermost levels of a hydrothermal system. Silicic alteration is often associated with porphyry copper and gold deposits, as well as other types of mineral deposits. The formation of silica minerals during silicic alteration results in the destruction of primary minerals, such as feldspar, and the creation of a more silicic-rich rock. The presence of silicic alteration is an important indicator of a hydrothermal system, and is often used in mineral exploration to help identify areas with a higher likelihood of hosting mineral deposits.
Advanced argillic alteration
Advanced argillic alteration is a type of hydrothermal alteration that results in the formation of clay minerals, such as kaolinite and dickite. It is typically found in the deeper levels of a hydrothermal system and occurs at higher temperatures than propylitic alteration. Advanced argillic alteration is characterized by the destruction of primary minerals, such as feldspar and mica, and the formation of clay minerals. The presence of advanced argillic alteration is often used as an indicator of a mineral deposit, particularly in the case of porphyry copper and gold deposits. The clay minerals formed during advanced argillic alteration can also act as a host for other minerals, such as gold and copper, making the alteration zone a potential target for exploration.
Potassic alteration or Potassium silicate alteration
Potassic alteration is a type of hydrothermal alteration that results in the formation of potassium-rich minerals, such as orthoclase, sanidine, and microcline. This type of alteration is typically associated with porphyry copper and gold deposits and is considered an important mineralization indicator. Potassic alteration occurs at intermediate to high temperatures and is characterized by the replacement of primary minerals, such as plagioclase and biotite, with potassium-rich minerals. Potassic alteration can also result in the formation of biotite and muscovite, which are important indicators of the intensity of alteration. The potassium-rich minerals formed during potassic alteration can also act as a host for other minerals, such as molybdenum and gold, making the alteration zone a potential target for exploration. The style and intensity of potassic alteration can vary greatly depending on the specific geologic setting and hydrothermal conditions.
Outcrop (a) and slab (b) photos of sodic-calcic altered quartz monzonite in Cherry Creek. The white stripe in outcrop is an aplite dike, several of which are flanked by sodic-calcic alteration – Freedman, David. (2018). Igneous and Hydrothermal Geology of the Central Cherry Creek Range, White Pine County, Nevada.
Sodic alteration refers to the type of hydrothermal alteration that results from the introduction of sodium into the host rock. This type of alteration is typically characterized by the presence of minerals such as albite, potassium feldspar, and sanidine. Sodic alteration is often associated with porphyry copper deposits and is often accompanied by other types of alteration such as phyllic and argillic alteration. The style and intensity of sodic alteration can provide important information for mineral exploration and the understanding of the mineralizing processes that took place during ore formation.
Quartz with Rutile, Novo Horizonte, Bahia, Northeast Region, BrazilRutile in quartz from Itabira, Brazil. Bristol City Museum and Art Gallery.
The name “rutile” is derived from the Latin word “rutilus,” which means “reddish.” This is because rutile can occur in various colors, including reddish-brown, black, yellow, and golden, depending on impurities present in the mineral. The crystal structure of rutile is tetragonal, with elongated prismatic crystals that are often striated.
Rutile has several important industrial applications due to its high refractive index and strong resistance to heat and chemical corrosion. One of its main uses is as a pigment in paints, plastics, ceramics, and other materials. It imparts a bright white color and excellent opacity to these products. Rutile is also used as a source of titanium metal, which has a wide range of applications in industries such as aerospace, automotive, electronics, and medical devices.
In addition to its industrial uses, rutile is valued as a collector’s mineral and gemstone. Transparent rutile crystals are sometimes cut and polished for use as gemstones. These specimens, known as “rutilated quartz,” display fine needle-like rutile inclusions that create unique and visually striking patterns within the quartz.
Rutile deposits are found worldwide, with significant reserves located in Australia, South Africa, India, and several other countries. The extraction of rutile typically involves mining operations, followed by processing to separate the mineral from other impurities. The processed rutile is then utilized in various industries according to its intended applications.
Overall, rutile is an important mineral with diverse uses, ranging from industrial applications to ornamental purposes. Its unique properties and widespread occurrence make it a valuable resource in numerous fields.
Rutile has one of the highest refractive indices at the real
wavelengths of all known crystals, and also has very high birefringence and
high dispersion. With these properties, it is possible to produce certain
optical elements, especially polarized optics, for infrared and infrared
wavelengths longer than about 4.5.
Natural Rutile can contain up to 10% iron and large amounts
of niobium and tantalum. Ruthyl was first described in 1803 by Abraham Gottlob
Werner.
Name: From the
Latin rutilus, red, in allusion to the color
Polymorphism &
Series: Trimorphous with anatase and brookite
Mineral Group: Rutile
group.
Diagnostic Features:
Characterized by its peculiar adamantine luster and red color. Lower specific
gravity distinguishes it from cassiterite.
Composition:
Titanium dioxide, Ti02. Ti = 60 per cent, 0 = 40 per cent. A little iron is
usually present and may amount to 10 per cent.
Crystallography:
Tetragonal; ditetragonal-dipyramidal. Prismatic crystals with dipyramid
terminations common (Fig. 315). Vertically striated. Frequently in elbow twins,
often repeated (Figs. 316 and 317). Twinning plane is dipyramid of second order
{Oil}. Crystals frequently slender acicular. Also compact massive.
The chemical composition of rutile is titanium dioxide (TiO2). It consists of one titanium atom bonded to two oxygen atoms, resulting in a ratio of 1:2.
Regarding its crystal structure, rutile belongs to the tetragonal crystal system. The crystal structure of rutile is based on a lattice arrangement of titanium and oxygen atoms. Each titanium atom is surrounded by six oxygen atoms, forming octahedral coordination. The oxygen atoms are positioned at the corners of the octahedron, while the titanium atom is located in the center. This arrangement creates a three-dimensional framework of interconnected octahedra.
The unit cell of rutile consists of two formula units (TiO2) and has a unique structure. It is characterized by elongated prismatic crystals with a distinct striated pattern. The striations, or parallel lines, are often observed on the crystal faces and result from the growth patterns during the mineral’s formation.
The crystal lattice of rutile is relatively rigid and stable, contributing to its resistance to heat, light, and chemical corrosion. This stability is advantageous in various applications, such as its use as a pigment and in the production of optical components.
It is important to note that while rutile is the most common and well-known form of titanium dioxide, there are other polymorphs of TiO2, including anatase and brookite. These polymorphs have different crystal structures and physical properties. Rutile is the most thermodynamically stable form at normal temperature and pressure conditions, while anatase and brookite are metastable forms that can transform into rutile over time under certain conditions.
Chemical Properties
Rutile, with the chemical formula TiO2, exhibits several important chemical properties:
Composition: Rutile is composed of titanium and oxygen atoms, with a ratio of one titanium atom to two oxygen atoms.
Stability: Rutile is a stable compound and is resistant to heat, light, and chemical corrosion. It retains its structural integrity under normal conditions.
Refractivity: Rutile has a high refractive index, which means it bends and slows down light more than many other materials. This property makes it valuable in the production of optical lenses, prisms, and high-quality glass.
Insolubility: Rutile is insoluble in water and most acids, including strong acids. It is also resistant to alkaline solutions.
Photocatalytic Properties: Rutile exhibits photocatalytic activity, meaning it can initiate chemical reactions under the influence of light. This property has led to its use in applications such as solar cells, wastewater treatment, and self-cleaning surfaces.
Redox Reactions: Rutile can participate in redox reactions, where it can either gain or lose electrons. For example, it can be reduced to titanium metal by reacting it with certain reducing agents.
Crystal Structure: Rutile has a tetragonal crystal structure, with titanium atoms arranged in octahedral coordination. The arrangement of atoms gives rutile its characteristic properties and shapes its physical and chemical behavior.
These chemical properties contribute to the diverse range of applications of rutile in various industries, including pigments, ceramics, optics, electronics, and more.
Distinct/Good
{110} distinct, {100} less distinct; and, {111} in
traces.
Diaphaneity
Transparent
Mohs Hardness
6 – 6,5
Crystal System
Tetragonal
Tenacity
Brittle
Density
4.23(2) g/cm3 (Measured) 4.25 g/cm3 (Calculated)
Fracture
Irregular/Uneven, Conchoidal, Sub-Conchoidal
Parting
On {092} due to twin gliding; also on {011}.
Other characteristics
Strongly anisotropic
Crystal habit
Acicular to Prismatic crystals, elongated and
striated parallel to [001]
Rutile Optical Properties
Type
Anisotropic
Anisotropism
Strong
Color / Pleochroism
Distinct; red, brown, yellow, green.
RI
values:
nω = 2.605 – 2.613 nε = 2.899 – 2.901
Twinning
Common on {011}, or {031}; as contact twins with
two, six, or eight individuals, cyclic, polysynthetic
Optic Sign
Uniaxial (+)
Birefringence
δ = 0.294
Relief
Very High
Dispersion:
Strong
Formation and Geologic Occurrence
Rutile forms through a variety of geologic processes and can be found in different geological settings. Here is an overview of its formation and geologic occurrence:
Magmatic Differentiation: Rutile can crystallize from magmas during the cooling and solidification of igneous rocks. Titanium-rich magmas, such as those associated with anorthosite and norite, provide favorable conditions for the formation of rutile. As the magma cools, minerals start to crystallize, and rutile can precipitate along with other minerals, such as quartz and feldspar.
Metamorphic Processes: Rutile commonly forms during regional or contact metamorphism, which involves high temperatures and pressures. During these processes, pre-existing minerals undergo transformations and recrystallization. Under the right conditions, minerals like ilmenite and titanite can undergo metamorphic reactions and produce rutile as a stable phase.
Hydrothermal Processes: Hydrothermal fluids, which are hot, mineral-rich solutions, can transport and deposit rutile in veins and fractures within rocks. These fluids are typically associated with igneous activity and can introduce titanium and oxygen into the rock formations. As the hydrothermal fluids cool and precipitate minerals, rutile can form along with other minerals in hydrothermal veins.
Placer Deposits: As mentioned earlier, rutile can be concentrated in placer deposits through weathering, erosion, and sedimentation processes. Over time, heavy minerals, including rutile, can be transported by water and accumulate in riverbeds, beaches, and coastal areas. The mechanical sorting action of water helps separate the denser rutile grains from lighter minerals, leading to their concentration in placer deposits.
Weathering and Sedimentary Processes: Weathering of primary rocks and subsequent erosion can release rutile into the sedimentary system. The detrital rutile can be transported by rivers, streams, and wind and eventually deposited in sedimentary basins. In sedimentary rocks, rutile grains can be found in sandstones, conglomerates, and other sedimentary formations.
It is important to note that the specific geological conditions and processes of rutile formation may vary depending on the location and geological history of a particular region. Rutile occurrences are often associated with other minerals such as ilmenite, zircon, magnetite, and various silicate minerals. Understanding the geological context and formation processes is crucial for the exploration and extraction of rutile deposits.
Industrial Applications of Rutile
Rutile has several important industrial applications due to its unique properties and characteristics. Some of the main industrial applications of rutile include:
Pigments: Rutile is widely used as a white pigment in paints, coatings, plastics, and paper. Its high refractive index and excellent opacity provide bright white color and good hiding power. Rutile pigments are known for their durability, weather resistance, and chemical stability, making them suitable for outdoor applications.
Ceramics: Rutile is utilized in the ceramics industry as an opacifier and a flux. It imparts opacity to ceramic glazes, allowing for vibrant and consistent colors. Rutile is also used as a fluxing agent in the production of ceramic bodies, helping to lower the melting point and improve the flow of the materials during firing.
Refractories: Rutile’s high melting point, thermal stability, and resistance to chemical corrosion make it valuable in the production of refractory materials. Refractories made with rutile can withstand high temperatures and harsh environments, making them suitable for applications in furnaces, kilns, and other high-temperature processes.
Welding Electrodes: Rutile is commonly used as a coating material for welding electrodes. The rutile coating provides stability and improves the arc characteristics during welding, ensuring a smooth and controlled welding process. The presence of rutile also contributes to the mechanical strength and quality of the welded joints.
Catalysts: Rutile exhibits photocatalytic properties, meaning it can initiate chemical reactions under the influence of light. This property is utilized in various environmental and energy applications, such as photocatalytic water splitting for hydrogen production, photovoltaic devices, and air purification systems.
Optics: Rutile’s high refractive index and transparency in the visible and near-infrared regions of the electromagnetic spectrum make it valuable in the production of optical components. Rutile is used in lenses, prisms, and polarizers for applications in cameras, microscopes, telescopes, and other optical instruments.
Electrodes and Electronic Components: Rutile can be processed into thin films and used as electrodes in electronic devices such as sensors, capacitors, and memory devices. It has good electrical conductivity and stability, making it suitable for these applications.
These are just some of the prominent industrial applications of rutile. Its unique combination of properties, including high refractive index, thermal stability, and chemical resistance, makes it a versatile and valuable material in various industries.
Rutile as a Gemstone
Rutile is also valued as a gemstone due to its unique inclusions and optical properties. The most common gemstone form of rutile is known as “rutilated quartz,” which consists of transparent quartz with needle-like rutile inclusions. These inclusions can vary in color, typically appearing golden, reddish-brown, or black.
The rutile inclusions in rutilated quartz create visually striking patterns and add beauty and interest to the gemstone. The fine and delicate needles of rutile can be distributed randomly or form organized patterns within the quartz, resembling rays, stars, or threads. These patterns are highly sought after by gemstone collectors and jewelry enthusiasts.
The optical effect caused by the rutile inclusions is known as chatoyancy or the “cat’s eye effect.” When properly cut and polished, rutilated quartz can exhibit a captivating chatoyant band that appears as a bright, shimmering line moving across the surface of the gemstone. This effect is caused by the reflection of light from the aligned rutile needles within the quartz.
Rutilated quartz is often used in various types of jewelry, including rings, pendants, earrings, and bracelets. It is typically cut into cabochons or faceted stones to showcase the unique inclusions and maximize their visual impact. The golden and reddish-brown varieties of rutilated quartz are especially popular due to their warm and eye-catching appearance.
In addition to rutilated quartz, other gemstones may also contain rutile as inclusions, although they are less common. These include rutile tourmaline and rutile topaz, where rutile needles are present within the crystal structures of these gemstones.
As with any gemstone, the value of rutilated quartz is influenced by factors such as clarity, size, color, and the quality and visibility of the rutile inclusions. Gems with well-defined, abundant, and evenly distributed rutile inclusions are generally considered more desirable.
Rutile as a gemstone offers a unique and visually appealing option for those seeking gemstones with distinctive characteristics and natural beauty. Its unusual inclusions and optical effects make rutilated quartz a fascinating choice for jewelry and gemstone enthusiasts.
Rutile Synthesis and Production
Rutile can be synthesized and produced through various methods, including both natural processes and laboratory techniques. Here are some common methods used for rutile synthesis and production:
Natural Formation: Rutile can naturally form through geological processes, as discussed earlier. It can crystallize from magmas during the cooling and solidification of titanium-rich igneous rocks. Additionally, metamorphic processes, hydrothermal activities, and weathering can contribute to the formation of rutile in natural settings over long periods of time.
Mineral Extraction and Processing: Rutile is commercially produced by mining and processing mineral deposits that contain significant amounts of rutile. The extraction process involves mining operations to access rutile-bearing ores, followed by various beneficiation techniques to separate rutile from other minerals and impurities. These techniques may include crushing, grinding, gravity separation, magnetic separation, and flotation.
Chemical Synthesis: Rutile can be synthesized in the laboratory using chemical methods. One common approach is the hydrolysis of titanium compounds, such as titanium chloride or titanium alkoxides, in the presence of appropriate reagents and conditions. This process allows for the controlled formation of rutile nanoparticles or larger rutile crystals.
Sol-Gel Method: The sol-gel method is another technique used for the synthesis of rutile. It involves the hydrolysis and condensation of precursor materials, typically metal alkoxides, to form a sol or gel-like solution. The sol or gel is then subjected to heat treatment to transform it into the desired rutile phase. This method allows for the production of rutile with controlled particle size, morphology, and crystallinity.
Vapor Deposition Techniques: Rutile can be produced through vapor deposition techniques such as chemical vapor deposition (CVD) and physical vapor deposition (PVD). These methods involve the introduction of precursor gases or vapor onto a substrate, where the rutile phase forms through chemical reactions or condensation. Vapor deposition techniques are often used to create thin films or coatings of rutile for various applications.
The specific synthesis method used for rutile production depends on the desired characteristics, particle size, and application requirements. Natural mineral deposits remain the primary source of commercial rutile, while laboratory synthesis methods are employed for specific research, engineering, and manufacturing purposes.
It’s worth noting that while rutile is an important mineral and widely available, its synthesis and production can be complex and require careful control of various parameters to achieve the desired quality and properties.
Rutile in Jewelry and Fashion
Rutile, particularly in the form of rutilated quartz, has gained popularity in the world of jewelry and fashion due to its unique and captivating appearance. Here’s how rutile is used in jewelry and fashion:
Rutilated Quartz Jewelry: Rutilated quartz is a popular gemstone used in various types of jewelry. The golden, reddish-brown, or black rutile inclusions within the transparent quartz create eye-catching patterns and add visual interest to the gemstone. Rutilated quartz is often cut into cabochons or faceted stones and used in rings, pendants, earrings, and bracelets. It is appreciated for its natural beauty and the chatoyant effect caused by the aligned rutile inclusions.
Statement Pieces: Rutile in jewelry is often used to create bold and statement pieces. The striking patterns and unique inclusions of rutilated quartz make it a centerpiece gemstone that stands out and captures attention. Jewelry designers incorporate rutilated quartz into large cocktail rings, dramatic pendants, and other statement pieces to create a visually impactful look.
Bohemian and Natural Styles: Rutile in jewelry complements bohemian and natural fashion styles. The earthy and organic look of rutilated quartz, with its golden or reddish-brown rutile inclusions, resonates well with the boho aesthetic. It is often used in combination with other natural materials like wood, leather, or woven fibers to create eclectic and free-spirited jewelry designs.
Fashion Accessories: Rutile can be utilized beyond traditional jewelry and incorporated into fashion accessories. Designers incorporate rutilated quartz into belt buckles, hairpins, cufflinks, and other fashion accessories to add a touch of natural beauty and uniqueness. The golden or reddish-brown rutile inclusions create an appealing contrast against various materials, making these accessories visually striking.
When wearing rutile jewelry or fashion accessories, it’s important to consider the stone’s care and maintenance. Like other gemstones, rutile should be protected from sharp blows, chemicals, and extreme temperatures to maintain its appearance and durability. Regular cleaning and proper storage are also recommended to preserve the beauty and longevity of rutile jewelry.
Rutile’s distinctive appearance and metaphysical associations make it a sought-after choice for those seeking jewelry and fashion items that are visually appealing and hold deeper meaning.
Distribution
Rutile is distributed worldwide, with significant deposits found in various countries across different continents. Here are some regions known for their rutile distribution:
Australia: Australia is one of the largest producers of rutile. Major rutile deposits are found in Western Australia, Queensland, and New South Wales. The Murray Basin in Victoria is particularly renowned for its extensive rutile resources.
South Africa: South Africa is another prominent producer of rutile. The mineral is found in the coastal regions of KwaZulu-Natal and the Eastern Cape. The Richards Bay Minerals (RBM) operation in KwaZulu-Natal is a significant source of rutile in the country.
India: India is known for its rutile resources, particularly in the coastal regions of Odisha, Tamil Nadu, and Kerala. These areas host substantial deposits of heavy minerals, including rutile.
Sierra Leone: Sierra Leone has significant rutile deposits along its coastline. The Sierra Rutile Mine in the southwestern part of the country is a major rutile mining operation.
Ukraine: Ukraine is home to substantial rutile resources, particularly in the region of Zhytomyr and Volyn. The deposits in these areas are associated with titanium-rich igneous rocks.
Brazil: Brazil has rutile deposits located in various states, including Minas Gerais, Rio de Janeiro, and Bahia. The Alto Horizonte Mine in Minas Gerais is an important rutile producer in the country.
Other Countries: Rutile deposits can also be found in several other countries, including the United States (primarily in Florida and Virginia), Madagascar, Mozambique, China, Sri Lanka, Norway, Canada, and many more.
It’s important to note that the distribution and abundance of rutile deposits can vary within each country, and ongoing exploration efforts may uncover new sources in previously unexplored regions. The availability of rutile in different areas contributes to its global supply for various industrial and commercial purposes.
References
Bonewitz, R. (2012). Rocks and minerals. 2nd ed.
London: DK Publishing.
Dana, J. D. (1864). Manual of Mineralogy… Wiley.
Handbookofmineralogy.org.
(2019). Handbook of Mineralogy. [online] Available at:
http://www.handbookofmineralogy.org [Accessed 4 Mar. 2019].
Mindat.org.
(2019): Mineral information, data and localities.. [online] Available at:
https://www.mindat.org/ [Accessed. 2019].
Wikipedia
contributors. (2019, June 10). Rutile. In Wikipedia, The Free Encyclopedia.
Retrieved 22:06, June 30, 2019, from
https://en.wikipedia.org/w/index.php?title=Rutile&oldid=901162262
Ore-bearing hydrothermal fluids are fluids that are enriched in minerals and metals, and play an important role in the formation of many types of mineral deposits. These fluids are typically hot and mineral-rich, and are often associated with igneous activity, such as volcanism or intrusions. The fluids can originate from a variety of sources, including magmatic fluids, metamorphic fluids, or meteoric fluids.
When these fluids move through rocks, they can cause changes in the rocks, such as the introduction of new minerals, alteration of existing minerals, and the creation of new structures, such as veins or breccias. As the fluids move through the rock, they can deposit minerals and metals along the way, resulting in the formation of ore deposits.
The exact mechanism by which these fluids transport and deposit minerals is complex and not fully understood. However, it is thought that the fluids can dissolve minerals from the surrounding rocks, and then transport them through fractures and pore spaces in the rock. As the fluids cool, the minerals can precipitate out of the fluid and form deposits.
The composition of the hydrothermal fluids can vary widely depending on their source, and can contain a variety of elements, including gold, silver, copper, lead, zinc, and uranium, among others. The presence of these metals can make the deposits economically valuable and important sources of minerals and metals for human use.
In geology, a fluid is a substance that can flow and take the shape of its container. Fluids are substances that have no fixed shape and can be either liquid or gas. They are a major component of many geological processes, such as the circulation of the Earth’s mantle, the formation of mineral deposits, and the movement of groundwater in the subsurface. Fluids play an important role in the transport of heat, mass, and energy, and are involved in a wide range of geological phenomena, including hydrothermal systems, volcanism, and tectonic deformation.
Hydrothermal fluid
Hydrothermal fluids are fluids that exist at high temperatures and pressures deep within the Earth’s crust. They are usually aqueous solutions that contain various dissolved substances, including minerals and gases, and can be rich in metals and other elements. Hydrothermal fluids can be generated by a variety of geological processes, including magmatic activity, the heating of groundwater by hot rocks, and the circulation of seawater through the oceanic crust. When these fluids come into contact with cooler rocks or are released to the surface, they can cause the formation of various types of mineral deposits, including gold, silver, copper, and lead-zinc deposits, among others. The study of hydrothermal fluids and their role in mineral deposit formation is an important part of economic geology.
Alteration and Leaching
Alteration and leaching are important geological processes that can lead to the formation of mineral deposits.
Alteration refers to the changes that occur in rocks due to the action of hydrothermal fluids. Hydrothermal fluids, which are superheated, mineral-rich water solutions, can alter the chemical and mineralogical composition of rocks. Alteration can occur through a variety of processes, such as hydration, oxidation, sulfidation, and silicification.
Leaching, on the other hand, is the process of dissolving minerals and other materials from rocks and soils through the action of water. This can occur when groundwater or other fluids percolate through rocks and soils, dissolving minerals and carrying them away. Leaching can be an important process in the formation of certain types of mineral deposits, such as oxide copper deposits and gold deposits.
Alteration and leaching can occur together, and can be important processes in the formation of many types of mineral deposits, particularly those formed by hydrothermal fluids. For example, alteration can lead to the formation of economic minerals through the precipitation of metals in the altered rock, while leaching can concentrate metals and other minerals in certain areas, leading to the formation of ore deposits.
The trinity model of the Au deposits with metallogenic porphyry, quartz vein and tectonically altered rocks of Ciemas, West Java, Indonesia. From Zhang, Zhengwei & Wu, Chengquan & Yang, XY & Zheng, Chaofei & Yao, Junhua. (2015). zhang zw-ogr-15. (https://www.researchgate.net/publication/284392400_zhang_zw-ogr-15)
Precipitation
In geology, precipitation refers to the formation and deposition of minerals from a solution. Precipitation is an important process in the formation of mineral deposits. When fluids carrying dissolved minerals are forced to change their conditions, such as temperature, pressure, or chemical composition, they may become supersaturated and can no longer hold the minerals in solution. The excess minerals then precipitate out of the fluid and form new mineral grains or crystals.
The precipitation process can occur in a variety of settings, including veins, disseminated deposits, and breccias. Precipitation can also occur as a result of hydrothermal alteration, in which minerals are altered by fluids that circulate through rocks. The alteration process can cause minerals to dissolve, become unstable, and reform in new configurations.
In addition to mineral deposits, precipitation can also occur in natural settings such as hot springs, geysers, and mineralized caves.
Precipitation
Types of water
Types of water
There are various types of water that can be associated with mineral deposits, depending on the geological setting. Some of the common types of water that can be encountered in mineral exploration and mining include:
Meteoric water: This is water that originates from precipitation and infiltrates into the ground, eventually reaching the water table.
Groundwater: This is water that occurs below the water table, and it can be found in aquifers or other underground reservoirs.
Surface water: This is water that occurs on the surface of the ground, such as in rivers, lakes, and oceans.
Hydrothermal water: This is hot water that originates from deep within the Earth’s crust, often associated with magmatic and hydrothermal mineral deposits.
Connate water: This is water that is trapped within sedimentary rocks during their formation, and can be encountered during mining.
Seawater: This is the water found in oceans and seas, and can be relevant for some types of mineral deposits that form in marine environments, such as evaporite deposits.
The type of water associated with a mineral deposit can have important implications for its exploration and mining, as well as for environmental considerations.
Black smoker hydrothermal vent at 2,980m depth, Mid-Atlantic Ridge.
Boiling process
Boiling process is a mechanism that can lead to the formation of mineral deposits in hydrothermal systems. When the temperature and pressure of the hydrothermal fluid drop to a certain point, the fluid can undergo boiling, resulting in the formation of steam bubbles. As the steam rises through the remaining hydrothermal fluid, it can carry with it dissolved mineral components, which can then precipitate out of solution as the fluid cools and the pressure decreases further. This can lead to the formation of mineral veins, as well as various types of mineral deposits, including gold and silver deposits, as well as some base metal deposits.
In addition to the precipitation of minerals from hydrothermal fluids due to boiling, other processes can also contribute to the formation of mineral deposits, including cooling, mixing, and reactions with rocks and other materials. The specific processes and conditions that lead to the formation of different types of mineral deposits can vary widely depending on a range of factors, including the type of mineral, the host rocks, and the specific geochemical and geological conditions present in the system.
Ilmenite an outstanding tabular group of large parallel-growth crystalsIlmenite-magnetite by James St. John (Flickr.com)
Ilmenite, otherwise called manaccanite, is a titanium-iron oxide mineral with formula: FeTiO3. It is a noteworthy wellspring of titanium. Typically thick and tabular, its crystals sometimes occur as thin lamellae (fine plates) or rhombohedra.. It can also be massive, or occur as scattered grains. Intergrowths with hematite or magnetite are common, and ilmenite can be mistaken for these minerals because of its opaque, metallic, gray-black color. Unlike magnetite, however, ilmenite is nonmagnetic or very weakly magnetic; and it can be distinguished from hematite by its black streak. It may weather to a dull brown color. It is widely distributed as an accessory mineral in igneous rocks, such as diorite and gabbro. It is a frequent accessory in kimberlite rocks, associated with diamond. It is also found in veins, pegmatite rocks, and black beach sands associated with magnetite, rutile, zircon, and other heavy minerals.
Name: For the early-noted occurrence in the Il’men Mountains,
Russia.
Polymorphism &
Series: Forms three series, with ecandrewsite, with geikielite, and with
pyrophanite.
Mineral Group: Ilmenite
group
Crystallography:
Rhombohedral; trigonal-rhombohedral. Crystals usually thick tabular with
prominent basal planes and small rhombohedral truncations. Faces of the third
order rhombohedron rare. Crystal constants close to those for hematite. Often
in thin plates. Usually massive, compact; also in grains or as sand.
IlmeniteComposition: Ferrous titanate, FeTi03. Fe = 36.8 per cent, Ti = 31.6 per cent, O = 31.6 per cent. By the introduction of ferric oxide, the ratio between the titanium and iron often varies widely. The excess of ferric oxide may be largely due to minute inclusions of hematite. Magnesium may replace the ferrous iron.
Diagnostic Features: It can be distinguished from hematite by its streak and from magnetite by its lack of magnetism. In doubtful cases, as in intergrowths with magnetite, it is necessary to apply the chemical tests.
Commonly thick tabular {0001}. Sometimes in thin
laminae; also acute rhombohedral. Compact massive; as embedded grains.
Other characteristics
weakly magnetic
Ilmenite Optical Properties
Type
Anisotropic
Anisotropism
Strong in shades of gray
Color / Pleochroism
Weak
Twinning
{0001} simple, {1011} lamellar
Optic Sign
Uniaxial (-)
Birefringence
Strong O=pinkish brown E= dark brown
Occurrence of Ilmenite
Ilmenite comes in the form of layers and lens bodies wrapped
in gneiss and other crystal metamorphic rocks. Common in veins or large masses
as a product of magmatic segregation. Associated with magnetite. Also as an
accessory mineral in igneous rocks. One component of black sand associated with
magnetite, rutile, zircon and monasite. Found in large numbers in Kragero and
other settlements in Norway; in crystals at Miask in the Ilmen Mountains, USA
Found in the United States in Washington, Connecticut; in Orange County, New
York and with many magnetite deposits in the Adirondack region. Also on Bay St.
to find Paul in Quebec
Uses Area
As a wellspring of titanium for paint shade. Can’t be
utilized as an iron mineral as a result of troubles in purifying it. In
addition, a modest quantity present in a magnetite body renders it of little
incentive as a metal.
It is the essential mineral of titanium metal. Limited quantities of titanium joined with specific metals will create sturdy, high-quality, lightweight combinations. These compounds are utilized to produce a wide assortment superior parts and instruments.
Models include: flying machine parts, counterfeit joints for
people, and donning hardware, for example, bike outlines. About 5% of the
ilmenite mined is utilized to create titanium metal. Some ilmenite is
additionally used to create engineered rutile, a type of titanium dioxide used
to deliver white, very intelligent shades.
The vast majority of the rest of the ilmenite is utilized to
make titanium dioxide, a dormant, white, exceptionally intelligent material.
The most significant utilization of titanium dioxide is as a whiting. Whitings
are white, exceedingly intelligent materials that are ground to a powder and
utilized as shades. These shades produce a white shading and splendor in paint,
paper, glues, plastics, toothpaste, and even sustenance.
Titanium dioxide is additionally used to make powders with a
firmly controlled molecule size range. These powders are utilized as modest
cleaning abrasives in an assortment of lapidary work that incorporates shake
tumbling, lapping, cabbing, circle making, and faceting. Titanium oxide
abrasives are utilized in numerous different businesses.
Varieties of Ilmenite (Mindat.com)
Cr-rich Picroilmenite
A cromium- and magnesium-rich variety of ilmenite, containing up to 8.6% Cr2O3 and up to 17.0% MgO.
Ferrian Ilmenite
containing up to 33% Fe2O3 in solid-solution in the rhombohedral series Fe2O3-FeTiO3.
Guadarramite
A supposed radioactive variety of ilmenite
Hystatite
A ferrian variety of ilmenite. On material from Arendal.
Iserine
A supposed cubic form of ilmenite.
Originally described from Jizerská meadow (Iser meadow),
Jizerské Mts (Iser Mts), Liberec Region, Bohemia (Böhmen; Boehmen), Czech
Republic.
Kibdelophane
A high Ti
Magnesian Chromian Ilmenite
A Mg-Cr-bearing variety from DeBeers mine (kimberlites), associated, i.a., with hawthorneite.
Magnesian Menaccanite
A magnesian variety of ilmenite.
Magnesian ilmenite
A variety of ilmenite with some Mg replacing Fe2+.
Magnetoilmenite
A ferrian variety of ilmenite.
Manaccanite
A ferrian variety. [Clark, 1993 – “Hey’s Mineral Index”]
Originally reported from Tregonwell Mill, Manaccan, Lizard
Peninsula, Cornwall, England, UK.
Manganilmenite
A manganian variety of ilmenite.
Manganoan Ilmenite
manganese-bearing variety of ilmenite. The pure Mn end-member is pyrophanite.
Picrocrichtonite
A magnesian variety of ilmenite.
Picroilmenite
A Mg-rich variety of ilmenite.
Picrotitanite
A magnesian variety of ilmenite.
Distribution
Widespread; well-crystallized from numerous localities.
In the Vishnevy-Il’men Mountains, Southern Ural
Mountains, Russia, large crystals; from the Lovozero massif, Kola Peninsula.
In Norway, at Tellnes and Snarum; large crystals
from Kragerøand Arendal. From Binntal, Valais, Switzerland.
At St. Cristophe, Bourg d’Oisans, Isere, France.
In the USA, at Quincy, Norfolk Co.,
Massachusetts; from Litchfield, Litchfield Co., Connecticut; large crystals
from the Lake Sanford area, Essex Co., New York.
At Allard Lake, Quebec; Bancroft, Ontario; and
elsewhere in Canada.
From Arkaroola Bore, Flinders Ranges, and near
Bimbowrie, South Australia.
References
Bonewitz, R. (2012). Rocks and minerals. 2nd ed.
London: DK Publishing.
Dana, J. D. (1864). Manual of Mineralogy… Wiley.
Handbookofmineralogy.org.
(2019). Handbook of Mineralogy. [online] Available at:
http://www.handbookofmineralogy.org [Accessed 4 Mar. 2019].
Mindat.org.
(2019): Mineral information, data and localities.. [online] Available at:
https://www.mindat.org/ [Accessed. 2019].
Nosean single crystal – Ochtendung, Eifel, GermanyNosean single crystal2 – Ochtendung, Eifel, Germany
Nosean, otherwise called Noselite, is a mineral of the feldspathoid type in tectosilicate with formula: Na8Al6Si6O24 (SO4). H2O. It frames isometric precious stones of variable shading: white, dim, blue, green, to dark colored. It has a Mohs hardness of 5.5 to 6 and a particular gravity of 2.3 to 2.4. It is fluorescent. It is found in low silica volcanic rocks. There is a strong arrangement among nosean and hauyne, which contains calcium.
Name: After Karl
Wilhelm Nose (1753?{1835), German mineralogist, of Brunswick (now Lower
Saxony), Germany
In Germany, at the Schellkopf, near Brenk, and
elsewhere around the Laacher See, Eifel district; at Dutchlingen and in the
HÄowenegg quarry, Hegau, Baden-WuÄrttemberg.
In the Mont-Dore massif, Auvergne, and at
Vinsac, Aldis, and Cournil, Cantal, France.
At Wolf Rock, Cornwall, England.
From Covao, Cape Verde Islands.
South of the Col de Maza, Morocco.
From the Black Hills, Lawrence Co., South
Dakota, and in the Cripple Creek district, Teller Co., Colorado, USA.
From the Lovozero massif, Kola Peninsula, Russia.
On Hsi Kuang T’a Men Mountain, Chiao Ch’eng
Mountains, Shansi Province, China.
References
Handbookofmineralogy.org.
(2019). Handbook of Mineralogy. [online] Available at:
http://www.handbookofmineralogy.org [Accessed 4 Mar. 2019].
Mindat.org.
(2019): Mineral information, data and localities.. [online] Available at:
https://www.mindat.org/ [Accessed. 2019].
Aliabad, Hunza Valley, Gilgit District, Gilgit-Baltistan (Northern Areas), Pakistan
Diopside is a member of pyroxene group mineral with formula is MgCaSi2O6. Specimens can be colorless but are more often bottle green, brownish green, or light green in color. It has two distinct prismatic cleavages at 87 and 93° typical of the pyroxene series. Diopside occurs in the form of equant to prismatic crystals that are usually nearly square in section. Crystals are less commonly tabular. This mineral can also form columnar, sheetlike, granular, or massive aggregates. Most diopside is metamorphic and found in metamorphosed silica-rich limestones and dolomites and in iron-rich contact metamorphic rocks. It also occurs in peridotites, kimberlites, and other igneous rocks. It forms complete solid solution series with hedenbergite (FeCaSi2O6) and augite, and partial solid solutions with orthopyroxene and pigeonite. .
Name: From two
Greek words meaning double and appearance, since the prism zone can apparently
be oriented in two ways.
Composition:
Calcium-magnesium silicate, CaMgSi20 6. CaO = 25.9 per cent, MgO = 18.5 per
cent, Si02 = 55.6 per cent. Iron may replace magnesium in all proportions, and
an isomorphous series exists between diopside and hedenbergite, CaFcSi20 6
Diagnostic Features:
Characterized by its crystal form, light color, and imperfect prismatic
cleavage at 87° and 93°.
Polymorphism &
Series: Forms two series, with hedenbergite, and with johannsenite
Mineral Group: Pyroxene
group.
Cell Data: Space
Group: C2=c: a = 9.746 b = 8.899 c = 5.251 ¯ = 105:63 ± Z = 4
Crystallography:
Monoclinic; prismatic. In prismatic crystals showing square or eight-sided
cross section. Also granular massive, columnar, and lamellar. Frequently
twinned polysynthetically with the basal pinacoid {001) the twin plane. Less
commonly twinned on the orthopinacoid {100}.
Simple and multiple twins common on {100} and {001}
Optic Sign
Biaxial (+)
Birefringence
δ = 0.030
Relief
High
Dispersion:
weak to distinct r > v
Elongation
parallel to c axis
Extinction
inclined in (010) sections
Occurrence
Diopside is characteristically found as a contact
metamorphic mineral in crystalline limestones. In such deposits it is
associated with tremolite, scapolite, idocrase, garnet, sphene. It is also found
in regionally metamorphosed rocks. The variety diallage is frequently found in
gabbros, peridotites, and serpentines.
Uses Area
Diopside-based ceramics and glass ceramics have
potential applications in various technological fields.
Transparent diopside varieties cut and gem
stones
Similarly, diopside-based ceramics and glass
ceramics have potential applications in the field of biomaterials in solid
oxide fuel cells, nuclear waste immobilization and sealing materials.
Distribution
Selected localities for ne crystals follow:
at Schwarzenstein, Zillertal, and near
PrÄagraten, Tirol, Austria.
From Ala, Piedmont, and St. Marcel, Val d’Aosta,
Italy.
At Otokumpu, Finland.
In Russia, at the Akhmatovsk deposit, near
Zlatoust, Ural Mountains; large crystals in the Inagli massif, 30 km west of
Aldan, Yakutia; and along the Slyudyanka River, near Lake Baikal, Siberia.
In Canada, many localities; in Ontario, at
Bird’s Creek, Eganville, Dog’s Lake, Littleeld, and Burgess; in Quebec, at Wakeeld,
Brompton Lake, near Magog, and in the Je®rey mine, Asbestos.
In the USA, at DeKalb, St. Lawrence Co., Natural
Bridge, Je®erson Co., Sing Sing, near Ossining, Westchester Co., New York; and
at Ducktown, Polk Co., Tennessee.
At Ampandrandava and Andranodambo, TaolanÄaro
(Fort Dauphin), Madagascar.
Large gemmy crystals from the Kunlun Mountains,
Sinkiang Uighur Autonomous Region, China.
From Tange-Achin, Kandahar Province,
Afghanistan.
Found near Jaipur, Rajasthan, India.
At Khapalu and Chamachu, Pakistan.
References
Bonewitz, R. (2012). Rocks and minerals. 2nd ed.
London: DK Publishing.
Dana, J. D. (1864). Manual of Mineralogy… Wiley.
Handbookofmineralogy.org.
(2019). Handbook of Mineralogy. [online] Available at:
http://www.handbookofmineralogy.org [Accessed 4 Mar. 2019].
Mindat.org.
(2019): Mineral information, data and localities.. [online] Available at:
https://www.mindat.org/ [Accessed. 2019].
Smith.edu.
(2019). Geosciences | Smith College. [online] Available at:
https://www.smith.edu/academics/geosciences [Accessed 15 Mar. 2019].
Lazurite is a member of sodalite group in feldspathoid mineral also it is tectosilicate with formula is (Na,Ca)8[(S,Cl,SO4,OH)2|(Al6Si6O24)]. A sodium calcium aluminosilicate, lazurite is the main component of the gemstonelapis lazuli and accounts for the stone’s intense blue color, although lapis lazuli also typically contains pyrite, calcite, sodalite, and haüyne. Lazurite specimens are always deep or vibrant blue.
Distinct crystals were thought to be rare until large
numbers were brought out of mines in Badakhshan, Afghanistan, in the 1990s.
These are usually dodecahedral and are much sought after. Most lazurite is
either massive or occurs in disseminated grains. Lapis lazuli is relatively
rare. It forms in crystalline limestones as a product of contact metamorphism.
The best quality lapis lazuli is dark blue with minor patches of calcite and
pyrite. In addition to its use as a gemstone, lapis lazuli was used as one of
the first eye shadows. (Bonewitz, 2012)
Lazurite crystallizes in the isometric system, although it
is well-formed crystals. Generally, massive and precious stone forms the mass
of lapis lazuli.
Name: For its
color resemblance to azurite, named from the Persian lazhward, for blue
Lazurite is a rare mineral, occurring usually in crystalline
limestones as a product of contact metamorphism. Lapis lazuli is usually a
mixture of lazurite with small amounts of calcite, pyroxene, and other
silicates, and commonly contains small disseminated particles of pyrite. The best
quality of lapis lazuli comes from northeastern Afghanistan. Also found at Lake
Baikal, Siberia; and in Chile.
Uses Area
Lapis lazuli is highly prized as an ornamental stone, for
carvings, etc. As a powder it was formerly used as the paint pigment ultra-marine.
Now ultramarine is produced artificially.
Distribution
Exceptional crystals from Sar-e-Sang, Badakhshan
Province, Afghanistan.
Well-crystallized material from the basins of
the Slyudyanka and Bystraya Rivers, Sayan Mountains, near Lake Baikal, Siberia,
Russia.
At Lyadzhuar-Darinsk, near Ishkashima, Pamir
Mountains, Tajikistan.
From Monte Somma, Campania, and in the Alban
Hills, Lazio, Italy.
In the USA, at Ontario Peak and Cascade Canyon,
San Bernardino Co., California, and on North Italian Mountain, Gunnison Co.,
Colorado.
In Canada, about 15 km north of Lake Harbour,
Ba±n Island, Northwest Territory.
At Thabapin, near Mogok, Myanmar (Burma).
From along the Cazadero River, near Ovalle,
Chile.
References
Bonewitz, R. (2012). Rocks and minerals. 2nd ed.
London: DK Publishing.
Dana, J. D. (1864). Manual of Mineralogy… Wiley.
Handbookofmineralogy.org.
(2019). Handbook of Mineralogy. [online] Available at:
http://www.handbookofmineralogy.org [Accessed 4 Mar. 2019].
Mindat.org.
(2019): Mineral information, data and localities.. [online] Available at:
https://www.mindat.org/ [Accessed. 2019].
