metamorphic

Milky quartz-rich rock (likely quartzite)

Quartzite; predominantly quartz (SiO₂), possibly with minor feldspar and iron-oxide staining

AI-generated identification · may be incorrect

White to cream, opaque, dull to slightly glassy luster, granular texture, and no obvious cleavage. Quartz hardness is about Mohs 7; the specimen should scratch ordinary glass, though weathering may reduce surface sharpness.

Identified September 7, 2026More metamorphic →

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Physical properties

Formation & geological history

Likely formed when quartz-rich sandstone was metamorphosed and recrystallized under heat and pressure. Its geological age cannot be determined from the photograph; quartzite occurs in many Precambrian and younger mountain belts.

Uses & applications

Used as building and decorative stone, aggregate, paving material, and occasionally as a lapidary or collectible specimen. This small weathered piece has modest commercial value.

Geological facts

The rusty tan patches are probably iron-oxide staining or weathered accessory minerals. A broken surface should look sugary and interlocking rather than showing distinct rounded sand grains.

Field identification & locations

Common in metamorphic terrains, mountain regions, and stream gravels. Confirm by testing a fresh edge with a steel nail and glass: it should resist the nail and scratch glass; fizzing with dilute acid would suggest carbonate contamination rather than pure quartzite.