Quartzite

Classification：Metamorphic Rock

Quartzite is a metamorphic rock composed mainly of quartz, which is usually formed by metamorphism of sandstone.

The main mineral of Quartzite is quartz, which contains mica minerals, hematite and goethite.
Quartzite is a metamorphic rock composed mainly of quartz (quartz content greater than 85%), which is formed by metamorphism of quartz sandstone and siliceous rock. It is usually formed by recrystallization of quartz sandstone or other siliceous rocks after regional metamorphism. It is also possible that the siliceous rocks near the magma formed Quartzite after thermal contact metamorphism.

The main chemical composition of Quartzite is quartz --SiO 2. Quartzite is generally massive, granular and crystallographic, with a crystalline aggregate. The color of quartz is also very rich. The common colors are green, gray, yellow, brown, orange red, white, blue, purple, red, etc.

The original rock of Quartzite can be: single mineral quartz sandstone, argillaceous and calcareous quartz sandstone, colloidal siliceous rocks (including siliceous rocks dissolving and redepositing by terrestrial debris and siliceous rocks associated with volcanic jets) and deep sea radiolarian siliceous rocks. Quartzite formed by different protolith can be distinguished according to structure, degree of crystallization, by-product, rock paragenesis and occurrence. For example, the Quartzite formed by single mineral quartz sandstone is coarser and often has a typical balanced mosaic structure, which contains more zircons and other accessory minerals. Quartzite, formed by siliceous rocks, is rarely more than 0.2 mm, even with advanced metamorphism, and has a dentate cross structure, usually without accessory minerals. [1]

Classification:
(1) feldspar Quartzite, quartz content is more than 75%, often contains feldspar and mica minerals, and feldspar content is generally less than 20%. If the feldspar content increases, the transition is to the shallow rock.
(2) Quartzite, quartz content is more than 90%, and can contain a small amount of minerals such as mica, feldspar, magnetite and so on.