Quartzite is a nonfoliated metamorphic rock composed almost absolutely of quartz. It paperwork while a quartz-rich sandstone is altered via the warmth, pressure, and chemical interest of metamorphism. These situations recrystallize the sand grains and the silica cement that binds them collectively. The result is a network of interlocking quartz grains of incredible power.
When sandstone is cemented to quartzite, the character quartz grains recrystallize along with the former cementing cloth to form an interlocking mosaic of quartz crystals.Most or all of the unique texture and sedimentary structures of the sandstone are erased through the metamorphism. The grainy, sandpaper-like surface turns into glassy in look.Minor amounts of former cementing substances, iron oxide, silica, carbonate and clay, often migrate during recrystallization and metamorphosis. This causes streaks and lenses to shape in the quartzite.
Texture: Granular.
Grain size: Medium grained; can see interlocking quartz crystals with the naked eye.
Hardness: Hard.
Colour: Pure quartzite is white but quartzite exists in a wide variety of colours.
Other features: Generally gritty to touch.
Contents
Chemical Composition
Quartzite is a metamorphic rock made from quartz sandstone, a sedimentary rock predominantly composed of the silicate mineral quartz. The chemical composite of the quartz minerals is silicon dioxide, written SiO2. The metamorphic forces of heat and pressure force the quartz minerals to bind together and crystallize into a strong matrix. This makes quartzite much harder on the Mohs scale (a measure of a rock’s hardness) than its parent rock of sandstone.
Formation of the Rock
Quartzite is metamorphosed sandstone. It is dominated by quartz, and in many cases, the original quartz grains of the sandstone are welded together with additional silica. Most sandstone contains some clay minerals and may also include other minerals such as feldspar or fragments of rock, so most quartzite has some impurities with the quartz.
Where is It Located
In the United States, formations of quartzite can be found in some parts of Pennsylvania, the Washington DC area, eastern South Dakota, Central Texas, southwest Minnesota, Devil’s Lake State Park in the Baraboo Range in Wisconsin, the Wasatch Range in Utah near Salt Lake City, Utah
In the United Kingdom, Cambrian “Hartshill quartzite” (Nuneaton area In Wales, Holyhead mountain and most of Holy island off Anglesey sport excellent Precambrian quartzite crags and cliffs. In the Scottish Highlands, several mountains composed of Cambrian quartzite can be found in the far north-west
In continental Europe, various regionally isolated quartzite deposits exist at surface level in a belt from the Rhenish Massif and the German Central Highlands into the Western Czech Republic, for example in the Taunus and Harz mountains. In Poland quartzite deposits at surface level exists in Świętokrzyskie Mountains.
In Canada, the La Cloche Mountains in Ontario are composed primarily of white quartzite. The highest mountain in Mozambique, Monte Binga (2436 m), as well as the rest of the surrounding Chimanimani Plateau are composed of very hard, pale grey, Precambrian quartzite. Quartzite is also mined in Brazil for use in kitchen countertops.
Characteristics and Properties of Rock
You needn’t be a geologist to appreciate the hardness and durability of quartzite.
Not only does this make for a tough stone, but it also makes it easy to tell quartzite from the imposters. Quartz is 7 on Mohs hardness scale. That means it’s harder than glass and harder than a knife blade.
Resistance to acids: Quartzite will not etch from acids like lemon juice or vinegar. Marble and dolomitic marble, on the other hand, will etch from these acids. Dolomitic marble etches slightly more slowly than regular marble. But quartzite will not etch at all from normal kitchen acids.
Porosity: Quartzite has a range of porosities. Some, like Taj Mahal or Sea Pearl, have been highly metamorphosed, and the minerals are bonded together tightly. White Macaubas and Calacatta Macaubas have been exposed to less intense pressure, so they are more porous and will benefit from sealing. if you prefer the beauty and color of quartzite, rest assured that you are selecting a material that is strong, beautiful, and very durable. These materials may be more scratch resistant, but they are not “scratch proof.” Quartzite is ideal for any countertop surface due to its strength and long-lasting composition. Consider quartzite countertops for its strength, beauty, and overall durability.
Uses of Rock
Quartzite is use for making bricks and other strong building materials. It is also growing in popularity as a decorative stone, and has a limited use as crushed stone. As it is so hard, quartzite is not quarried as much as softer stone, and tends to be taken from the surface rather than underground. Quartzite is also quite dense and extremely hard. Crushed quartzite can be use as railroad track ballast because is so hard and durable.
Quartzite is extremely versatile and can be used both indoors and outdoors. It can be used in many different shapes and forms including landscaping, building stone, as a feature wall, tiles or even stone cladding.
Some of the most common uses indoors are floors, countertops, vanities, fireplace surrounds, etc.
Facts About Rock
Quartzite is the result of sandstone and the mineral quartz being put under extreme heat and pressure.
At least ninety percent of a quartzite rock is quartz.
Quartzite is usually white or a light shade of pink or gray.
Mountains and hillsides are typical places to find quartzite.
Quartzite tends to be smooth with a grainy and lustrous appearance.
The purest form of silica found on Earth can be found in quartzite.
Bricks and other strong building material are made of quartzite.
Quartzite tends to be very strong and thick so it is taken from the Earth’s surface rather than mined underground.
The shade of quartzite is dependent upon the amount of iron oxide that is present.
Hilltops made of quartzite usually do not change because quartzite is resistant to weathering.
The bedding around railroad tracks often contains quartzite because of its durability.
Quartzite is very versatile in construction and is used as flooring, decorative wall coverings, and roofing.
During the Stone Age when flint was not available, quartzite was often used as a replacement.
Quartzite can be found in many countries including Canada, the United Kingdom, and the United States.
Because of the high amount of silica in quartzite, the soil around the developing quartzite does not have enough nutrients to sustain vegetation.
References
Bonewitz, R. (2012). Rocks and minerals. 2nd ed. London: DK Publishing.
http://www.softschools.com/facts/geology/quartzite_facts/386/