metamorphic

Likely quartz-rich metamorphic rock (quartzite or micaceous schist)

Quartzite/schist; predominantly quartz (SiO₂) with mica and minor iron oxides

AI-generated identification · may be incorrect

Gray, coarse-grained, sparkly surface with granular interlocking crystals and rusty staining; likely Mohs 6.5–7, vitreous to dull luster, no obvious cleavage, and specific gravity about 2.6–2.8.

Identified September 4, 2026More metamorphic →

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Physical properties

Gray, coarse-grained, sparkly surface with granular interlocking crystals and rusty staining; likely Mohs 6.5–7, vitreous to dull luster, no obvious cleavage, and specific gravity about 2.6–2.8.

Formation & geological history

Formed when quartz-rich sandstone or a mica-bearing protolith was buried and recrystallized under heat and pressure, commonly during mountain building; its exact geological age cannot be determined from the photograph.

Uses & applications

Useful as crushed aggregate, road stone, landscaping material, and occasionally dimension stone; generally has little jewelry value unless unusually attractive or distinctly mineralized.

Geological facts

The reflective flakes are probably mica, while the hard gray grains are likely quartz; iron oxides produce the brown-rust patches.

Field identification & locations

Common in metamorphic belts worldwide. A glass-scratch test, visible foliation, and acid test help distinguish quartzite from carbonate rocks; identification is uncertain without a fresh surface or thin section.