Often confused with quartz because of the similarity of names , quartzite is a natural stone, not an engineered one. The peculiarities of its formation make quartzite extremely hard and highly resistant to heat and water. It comes in various textures and colors and easily withstands heavy foot traffic and harsh weather conditions.
Due to this exceptional durability and versatility, quartzite can be used in all kinds of exterior and interior applications. Quartzite has many advantageous properties, but its gorgeous look and unparalleled durability are, undoubtedly, the most notable ones:.
As already mentioned, quartzite is a naturally occurring metamorphic rock. It is formed when intense heat and strong pressure caused by tectonic plate compression in the crust of the earth cause the individual grains within pure quartz sandstone to recrystallize and form an interlocking mosaic of quartz crystals.
The resulting metamorphosed stone loses most or all of the original texture and sedimentary structures of the sandstone and becomes extremely hard and resistant to harsh chemical attacks, abrupt temperature changes, and general wear and tear. As a matter of fact, quartzite has been given a hardness reading of eight out of ten on the Mohs Hardness Test the scale that measures the hardness of a material.
This means that it is harder than glass and must be cut with diamond blades when necessary. The incredible strength of quartzite makes it one of the most durable natural stones available on the market. It resists heat and cold without cracking or sustaining other damage when exposed to extreme temperatures. When heat and pressure work on quartz-rich sandstone, the resulting hard metamorphic rock is called quartzite. Quartzite contains at least 90 percent quartz, and because quartzite is metamorphic, it is hard, compact and resists weathering.
It is often found on hills or mountain masses, such as on some ridges of the Appalachian Mountains, according to the Geological Sciences Department at California Polytechnic State University, Pomona.
But quartzite formations are found the world over, including in the United States, Canada, Norway, Sweden, Italy and South Africa, though this list is by no means exhaustive.
She has more than 16 years of experience in transcribing and editing medical reports. Jaines holds a Bachelor of Arts in telecommunications and journalism from Northern Arizona University. Types of Rocks Found in the Himalayas. Properties of Igneous Rocks for Kids.
Color Usually white or gray, can be other colors, due to impurities. Related topics: Silicon Element. Aggregates Teacher Guide. Some rock units that are stained by iron can be pink, red, or purple. Other impurities can cause quartzite to be yellow, orange, brown, green, or blue. The quartz content of quartzite gives it a hardness of about seven on the Mohs Hardness Scale. Its extreme toughness made it a favorite rock for use as an impact tool by early people.
Its conchoidal fracture allowed it to be shaped into large cutting tools such as ax heads and scrapers. Its coarse texture made it less suitable for producing tools with fine edges such as knife blades and projectile points. Obsidian , flint and agate were better suited for tools where sharpness was important. Quartzite scree: A steep slope covered with an unstable blanket of quartzite scree. Scree is a name used for resistant pieces of broken rock that cover a talus slope.
This photo was taken near Begunje na Gorenjskem, Slovenia. A Creative Commons image by Pinky sl. Most quartzite forms during mountain-building events at convergent plate boundaries where sandstone was deposited on a continental plate. There, the sandstone is metamorphosed into quartzite by the intense pressure of a plate collision and often by deep burial.
Compressional forces at the plate boundary fold and fault the rocks and thicken the crust into a mountain range. Quartzite is an important rock type in folded mountain ranges throughout the world. Catoctin Mountain is part of the Blue Ridge Mountains. The Chimney Rock Formation in this area caps many of the ridges, drapes the flanks of the mountains as scree, and is made up mostly of quartzite. Quartzite is one of the most physically durable and chemically resistant rocks found at Earth's surface.
When mountain ranges are worn down by weathering and erosion, less-resistant and less-durable rocks are destroyed, but the quartzite remains. This is why quartzite is so often the rock found at the crests of mountain ranges and covering their flanks as large boulders, or as a surface litter of scree.
Quartzite is also a poor soil-former. Unlike feldspars which break down to form clay minerals, the weathering debris of quartzite is quartz. It is therefore not a rock type that contributes well to soil formation. For that reason it is often found as exposed bedrock with little or no soil cover. Fuchsitic Quartzite: A specimen of quartzite that contains significant amounts of green fuchsite, a chromium-rich muscovite mica.
This specimen measures about 7 centimeters across and was collected from a small abandoned quarry where the flaggy rocks were produced and cut for use as decorative stones. Photograph by James St. John, used here under a Creative Commons license. Geologists have used the name "quartzite" in a few different ways, each with a slightly different meaning.
Today most geologists who use the word "quartzite" are referring to rocks that they believe are metamorphic and composed almost entirely of quartz. A few geologists use the word "quartzite" for sedimentary rocks that have an exceptionally high quartz content. This usage is falling out of favor but remains in older textbooks and other older publications.
The name "quartz arenite" is a more appropriate and less confusing name for these rocks.
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