mineral

Likely quartz-rich rocks

Possibly massive quartz (SiO₂); the photo is insufficient for a confident identification.

AI-generated identification · may be incorrect

The left specimen is rough, tan, and granular; the right is pinkish-brown with a glossy surface that may be natural fracture or coating. Quartz has Mohs hardness 7, vitreous luster, hexagonal crystals, and no cleavage, but these specimens’ properties cannot be confirmed from the image.

Identified September 26, 2026More mineral →

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Physical properties

Formation & geological history

If quartz, it formed when silica-rich fluids crystallized in veins or cavities, or as grains in rock; the age and setting are unknown.

Uses & applications

Quartz is used in glass, electronics, abrasives, construction, and jewelry; these pieces appear to be unworked or of modest specimen quality.

Geological facts

Quartz is one of Earth’s most abundant minerals and occurs in many colors and rock types.

Field identification & locations

Check hardness against glass and examine fresh surfaces for glassy luster and lack of cleavage; location and tests are needed to distinguish quartz from other rocks.