Quartzite Tile and Random Quartzite
Quartzite is a hard, metamorphic rock which was originally sandstone. Through heating and pressure usually related to tectonic compression within orogenic belts, the original quartz sand grains and quartz silica cement were fused into one.
Pure quartzite is usually white to grey. Differing mineral content creates many color variations, from the sedate white, gray or beige to more adventurous shades of purple and pink, due to varying amounts of iron oxide. Other colors are due to impurities of minor amounts of other minerals.
Orthoquartzite is a very pure quartz sandstone composed of usually well rounded quartz grains cemented by silica. Orthoquartzite is often 99% SiO2 with only very minor amounts of iron oxide and trace resistant minerals such as zircon, rutile and magnetite. Although few fossils are normally present the original texture and sedimentary structures are preserved.
In true metamorphic quartzite, also called meta-quartzite, the individual quartz grains have recrystalized along with the former cementing material to form an interlocking mosaic of quartz crystals. Minor amounts of former cementing materials, iron oxide, carbonate and clay, are often recrystalized and have migrated under the pressure to form streaks and lenses within the quartzite. Virtually all original textures and structure have usually been erased by the metamorphism.
Quartzite is very resistant to chemical weathering and often forms ridges and resistant hilltops. The nearly pure silica content of the rock provides little to form soil from and therefor the quartzite ridges are often bare or covered only with a very thin soil and little vegetation.
Shimmering and sparkling with tiny quartz crystals, Quartz is a rock similar to slate with a medium grained texture and incredible durability. They are so close to slates that usually they are referred to as quartzitic-slates; and just like slates, they are used for various applications depending on their hardness. A naturally non-skid texture makes it a perfect candidate for indoor floors and outdoor flooring, including areas with heavy traffic and exposure to the elements. Quartzite is also used for wall veneers and decorative tiles. Because of its hardness (about 7 on Mohs' scale of mineral hardness), crushed quartzite is often used as railway ballast.