mineral

Quartz-rich pebble, possibly milky quartz or quartzite

Quartz (SiO₂), potentially metamorphic quartzite

AI-generated identification · may be incorrect

Small rounded specimen with a white to gray, opaque appearance and scattered tan/brown surface staining; likely glassy to dull luster. Quartz has Mohs hardness 7, no cleavage, conchoidal fracture, and specific gravity about 2.65; quartzite is a tightly interlocked quartz aggregate.

Identified August 19, 2026More mineral →

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Physical properties

Formation & geological history

It may be a naturally worn quartz fragment or quartzite pebble formed by metamorphism of sandstone. Quartz is widespread and commonly Precambrian to recent in age; the image alone cannot establish a precise age or locality.

Uses & applications

Quartz is used in glass, ceramics, electronics, abrasives, and engineered stone; attractive pieces may be used as inexpensive decorative specimens. Ordinary pebbles generally have minimal commercial value.

Geological facts

The hardness test is useful: it should scratch ordinary glass but not be scratched by a steel knife. Brown patches may be iron-oxide staining, weathering, or attached sediment.

Field identification & locations

Common in stream gravels, quartz veins, beaches, and weathered mountain terrains worldwide. A streak test, glass-scratch test, and close inspection for visible interlocking grains can distinguish quartz from quartzite.