metamorphic

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly crystalline SiO₂, possibly with mica or feldspar

AI-generated identification · may be incorrect

Gray to tan, granular texture, and vitreous to dull luster; quartz hardness is about Mohs 7, with no obvious cleavage and irregular fracture. The specimen appears fine- to medium-grained and weathered, but an image cannot confirm its exact mineralogy.

Identified September 8, 2026More metamorphic →

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Physical properties

Formation & geological history

Forms when quartz-rich sandstone is recrystallized under heat and pressure during regional metamorphism, commonly in mountain belts. Its age depends on the source sandstone and metamorphic event; no precise age can be determined visually.

Uses & applications

Used as crushed stone, road aggregate, building stone, and decorative slabs; attractive pieces may be collected but this specimen shows no obvious gem value.

Geological facts

Quartzite is generally harder and more resistant to weathering than sandstone, and individual sand grains may be fused into an interlocking quartz mosaic.

Field identification & locations

Common in metamorphic terrains and mountain regions worldwide; test with a steel file or glass—quartzite should scratch glass and resist a steel knife. A streak, acid test, and fresh broken surface would improve identification.