metamorphic

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly crystalline SiO₂ with possible iron-oxide and mica impurities

AI-generated identification · may be incorrect

Hardness about 7 Mohs; coarse, interlocking translucent gray-white quartz grains with brown iron-oxide staining and darker mineral inclusions; vitreous to dull luster, massive texture, and no obvious cleavage.

Identified September 6, 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 Precambrian to younger mountain belts. The brown coloration likely comes from weathering of iron-bearing minerals.

Uses & applications

Used as crushed stone, aggregate, decorative stone, and occasionally as lapidary material; attractive pieces may be polished, though this specimen appears rough and weathered.

Geological facts

Quartzite breaks across grains rather than around them and is generally harder and more resistant to weathering than its sandstone precursor.

Field identification & locations

Identify it by its sugary crystalline texture, lack of bedding, glassy quartz grains, and inability to scratch quartz; common in metamorphic mountain regions worldwide. A definitive identification may require a fresh surface or thin-section examination.