Celestine, also known as celestite, is a mineral that belongs to the sulfate mineral group. It is named after the Latin word “caelestis,” which means “heavenly” or “celestial,” due to its beautiful sky-blue color. Celestine is often found in sedimentary rocks and frequently occurs in association with other minerals such as gypsum, calcite, and sulfur.

One of the distinctive features of celestine is its crystal structure, which is orthorhombic. It forms prismatic crystals with a characteristic tabular habit and often exhibits well-developed faces and sharp edges. The crystals can range in size from small to quite large and can occur as individual crystals or as clusters.

The color of celestine is typically pale blue to sky blue, although it can also be colorless, white, or even yellow. The blue color is due to the presence of trace amounts of strontium within its crystal lattice. In terms of transparency, celestine is usually transparent to translucent.

Celestine has a moderate hardness of 3 to 3.5 on the Mohs scale, meaning it can be scratched by a knife but not by a fingernail. It has a perfect cleavage along the crystal faces, which means it can easily split into thin, flat fragments. The mineral also has a vitreous to pearly luster when polished.

One of the notable occurrences of celestine is in Madagascar, where some of the finest and largest crystals have been found. Other significant deposits can be found in countries such as the United States, Mexico, Brazil, China, and Iran.

Besides its aesthetic appeal as a gem mineral, celestine also has various industrial uses. It is a source of strontium, which is used in the production of fireworks, flares, and pyrotechnics due to its ability to produce a vibrant red color. Strontium compounds derived from celestine are also used in the manufacturing of glass, ceramics, and certain types of batteries.

In terms of metaphysical and spiritual beliefs, celestine is often associated with tranquility, harmony, and divine connection. Some individuals believe that celestine possesses healing properties and can promote a sense of peace, clarity, and spiritual awakening.

In summary, celestine is a captivating mineral known for its sky-blue color, orthorhombic crystal structure, and moderate hardness. It is prized both for its aesthetic appeal and industrial applications, particularly as a source of strontium. Whether appreciated for its beauty or its potential metaphysical properties, celestine continues to captivate and intrigue people around the world.

Geological Formation

Celestine typically forms in sedimentary environments through the following geological processes:

  1. Weathering and Erosion: Strontium-rich rocks, such as limestone and dolomite, undergo weathering and erosion, releasing strontium ions (Sr2+) into the surrounding environment.
  2. Groundwater Interaction: The strontium ions in the groundwater interact with sulfate ions (SO42-) derived from various sources like volcanic activity or evaporite deposits. This interaction occurs in an aqueous solution.
  3. Precipitation: Under specific conditions, the sulfate and strontium ions become supersaturated in the groundwater solution. This leads to the precipitation of celestine crystals as the solution cools and evaporates.
  4. Crystal Growth: Over time, the celestine crystals grow in size, aided by favorable factors like a slow rate of evaporation, high sulfate and strontium concentrations, and suitable nucleation sites for crystal growth.

Chemical Composition

The chemical composition of celestine is as follows:

  1. Chemical Formula: SrSO4
  2. Elements: Celestine consists of strontium (Sr), sulfur (S), and oxygen (O) elements.
  3. Strontium Content: Strontium is the dominant element in celestine, making up a significant portion of its chemical composition.
  4. Sulfate Ion: Celestine contains the sulfate ion (SO42-), which combines with strontium to form the mineral.

Physical Properties

Here are the physical properties of celestine:

  1. Color: Celestine is primarily known for its blue color, ranging from pale blue to a deeper sky blue. It can also be colorless, white, yellow, or grayish.
  2. Crystal Structure: Celestine has an orthorhombic crystal structure, characterized by three axes of different lengths that are perpendicular to each other.
  3. Hardness: It has a hardness of 3 to 3.5 on the Mohs scale, making it relatively soft compared to many other minerals.
  4. Cleavage: Celestine exhibits perfect cleavage along the crystal faces, allowing it to be easily split into thin, flat fragments or sheets.
  5. Luster: When polished, celestine displays a vitreous to pearly luster.
  6. Transparency: Celestine is typically transparent to translucent, allowing light to pass through. Thicker specimens may appear more opaque.
  7. Density: The density of celestine ranges from approximately 3.9 to 4.0 grams per cubic centimeter.
  8. Solubility: It is soluble in hydrochloric acid.
  9. Texture: Celestine often exhibits a fibrous or granular texture.

These physical properties contribute to the appearance and characteristics of celestine, making it recognizable and distinct as a mineral.

Occurrence and Distribution

Global Distribution: Celestine is found in various regions around the world. Some of the notable countries where celestine deposits have been discovered include:

  1. Madagascar: Madagascar is renowned for its high-quality celestine crystals. The Sakoany deposit in the Mahajanga Province of Madagascar is particularly famous for producing large and well-formed celestine specimens.
  2. United States: Celestine deposits can be found in several states within the United States. Notable locations include California (San Bernardino County), Ohio (Muskingum County), and New York (Schoharie County).
  3. Mexico: Mexico is another significant producer of celestine. The state of Coahuila, in particular, is known for its deposits, with the Sabinas and Múzquiz municipalities being notable sources.
  4. Brazil: Celestine deposits are found in several regions of Brazil, including Rio Grande do Sul, Paraná, and Bahia.
  5. China: China has substantial celestine reserves, with deposits located in various provinces such as Guangxi, Hunan, and Jiangsu.
  6. Iran: Celestine deposits occur in several areas of Iran, including the Kerman and Semnan provinces.
  7. Other Countries: Celestine can also be found in other countries such as Italy, Spain, Poland, Russia, the United Kingdom, Canada, and Morocco, among others.

Deposits and Mining Locations

Mining operations for celestine are primarily focused on extracting strontium, which is used in various industrial applications. Some notable mining locations for celestine include:

  1. Strontian, Scotland: The town of Strontian in Scotland gave its name to the element strontium. The original discovery of strontium minerals, including celestine, was made in this area.
  2. Sakoany, Madagascar: The Sakoany deposit in Madagascar is a well-known source of high-quality celestine crystals. Mining operations have been conducted to extract and collect these specimens.
  3. San Bernardino County, California, USA: The Imperial Mine and Pugh Quarry in California have been productive sources of celestine. They have been mined for both the mineral’s aesthetic value and its industrial applications.
  4. Coahuila, Mexico: The state of Coahuila in Mexico has significant celestine deposits, particularly in the Sabinas and Múzquiz municipalities. Mining operations are carried out to extract strontium from the ore.
  5. Guangxi Province, China: Celestine deposits in Guangxi Province, China, have been actively mined to extract strontium and its compounds.
  6. Other Locations: Celestine mining operations also exist in various other regions globally, depending on the occurrence of economically viable deposits.

It’s important to note that the specific mining locations and the status of mining operations may vary over time, as new deposits are discovered, and existing ones are exhausted or become economically unviable.

Uses and Applications

Celestine has several practical uses and applications due to its strontium content. Here are some notable uses:

  1. Strontium Compounds: Celestine is an important source of strontium, which is extracted and processed to produce various strontium compounds. These compounds have diverse applications in different industries, including:a. Pyrotechnics: Strontium compounds are used in fireworks and flares to produce brilliant red colors.b. Glass and Ceramics: Strontium compounds are used as additives in the manufacturing of glass and ceramics to enhance properties such as transparency, hardness, and thermal resistance.c. Television and Electronics: Strontium compounds, particularly strontium ferrite, are used in the production of magnets for television and electronic devices, such as speakers and hard drives.d. Radiography: Strontium compounds have been used in medical radiography as contrast agents to enhance imaging.
  2. Gemstone and Mineral Specimens: Celestine is appreciated by collectors and enthusiasts for its aesthetic qualities. It is often cut and polished into gemstones or used in mineral specimen collections due to its sky-blue color, crystal habit, and luster.
  3. Industrial Applications: Celestine’s physical properties make it suitable for various industrial applications, including:a. Cement: Celestine is used as a minor additive in cement production to improve the strength and durability of concrete.b. Battery Manufacturing: Strontium compounds derived from celestine are used in certain types of batteries, such as nickel-metal hydride (NiMH) batteries.c. Environmental Applications: Strontium compounds, particularly strontium sulfate, are used in wastewater treatment to remove contaminants and improve water quality.
  4. Metaphysical and Spiritual Beliefs: Some individuals believe that celestine possesses metaphysical properties and promotes spiritual growth, clarity, and tranquility. It is sometimes used in crystal healing practices, meditation, and energy work.

It’s important to note that while celestine has various applications, its usage may vary depending on factors such as availability, cost, and specific industry requirements.

Recap of Key Points

  • Celestine, also known as celestite, is a mineral belonging to the sulfate mineral group.
  • It is named after the Latin word “caelestis,” meaning “heavenly” or “celestial,” due to its beautiful sky-blue color.
  • Celestine is primarily formed in sedimentary environments through the interaction of strontium and sulfate ions in supersaturated groundwater solutions.
  • The mineral has an orthorhombic crystal structure, forming prismatic crystals with well-defined faces and edges.
  • Celestine exhibits a range of colors, including pale blue to deep blue, as well as colorless, white, yellow, or grayish shades.
  • Its physical properties include a hardness of 3 to 3.5 on the Mohs scale, perfect cleavage along crystal faces, vitreous to pearly luster, and transparency to translucency.
  • Celestine is found in various countries globally, including Madagascar, the United States, Mexico, Brazil, China, and Iran.
  • It is mined for its strontium content, which is used in applications such as pyrotechnics, glass and ceramics manufacturing, electronics, cement production, and batteries.
  • Celestine is valued for its aesthetic appeal and is used as gemstones or in mineral specimen collections.
  • Some individuals associate metaphysical and spiritual properties with celestine, believing it promotes tranquility, clarity, and spiritual growth.


What is the difference between celestine and celestite?

“Celestine” and “celestite” are often used interchangeably and refer to the same mineral. Celestine is the mineral’s official name, while “celestite” is a variation of the name commonly used in the industry and by collectors.

What gives celestine its blue color?

Celestine’s blue color is attributed to trace amounts of strontium within its crystal structure. The presence of strontium imparts the characteristic sky-blue hue.

Is celestine a valuable gemstone?

Celestine is valued as a gemstone by collectors and enthusiasts. However, its value primarily depends on factors such as the quality, size, and aesthetics of the specimen.

Can celestine be used for jewelry?

Celestine is not widely used in commercial jewelry due to its relatively low hardness. It is considered a softer mineral and requires gentle handling to avoid scratching or damage.

What are the industrial applications of strontium derived from celestine?

Strontium derived from celestine is used in various applications. It is employed in pyrotechnics, glass and ceramics manufacturing, electronics, cement production, batteries, and wastewater treatment, among others.

Is celestine radioactive?

No, celestine is not radioactive. It does not possess any inherent radioactivity.

Can celestine be found in jewelry stores?

Celestine is not commonly found in mainstream jewelry stores. It is primarily sought after by collectors and can be obtained through mineral and gemstone specialty stores, online auctions, or gem shows.

How can I identify celestine?

Celestine can be identified by its distinctive sky-blue color, perfect cleavage, orthorhombic crystal structure, and a hardness of 3 to 3.5 on the Mohs scale. Chemical testing can also confirm the presence of strontium and sulfate ions.

Is celestine a common mineral?

Celestine is not as abundant as some other minerals. While it can be found in various locations worldwide, high-quality and large crystals are relatively rare, making them more valuable to collectors.