Quartzite

Hardness of 7 on the Mohs scale, colors range from white and gray to shades of pink, brown, and yellow, vitreous to greasy luster, non-foliated massive crystal structure, conchoidal fracture, specific gravity around 2.65.

Formed from quartz-rich sandstone or chert under high temperature and pressure conditions during regional or contact metamorphism. Geological age varies widely depending on the formation site, ranging from Precambrian to Cenozoic.

Used in construction, building facades, roofing tiles, decorative aggregates, crushed stone for roadbeds, and occasionally for countertops and sculptures.

Pure quartzite is one of the most chemically inert and physically durable rocks on Earth, making it highly resistant to weathering and erosion, often forming prominent mountain ridges.

Can be identified in the field by its sandy texture that does not scratch easily with a knife, its inability to fizz with dilute hydrochloric acid, and the interlocking quartz crystals visible under a hand lens. Commonly found in mountainous regions and ancient cratons worldwide.