mineral

Rounded quartz-rich pebble

Likely microcrystalline quartz (SiO₂), possibly milky quartz or a pale quartzite fragment

AI-generated identification · may be incorrect

Off-white, smooth and water-worn with a dull to weakly waxy luster; likely hardness about 7 Mohs, no visible cleavage, conchoidal fracture, and specific gravity near 2.65. The fine texture could also indicate quartzite or a pale chert, but the photograph alone cannot distinguish these confidently.

Identified August 13, 2026More mineral →

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Physical properties

Formation & geological history

Probably formed as quartz-rich rock or silica vein material, then rounded by stream, beach, or tumbling abrasion. Quartz commonly formed in Precambrian to younger igneous, metamorphic, and sedimentary settings; its exact age is indeterminable from the image.

Uses & applications

Common pebbles have little commercial value, but similar material is used as aggregate, landscaping stone, abrasives, silica feedstock, and occasionally in carvings or decorative jewelry.

Geological facts

Quartz is one of Earth’s most abundant minerals and is resistant to weathering, allowing it to survive transport as rounded pebbles.

Field identification & locations

Test cautiously with a steel file or knife: quartz should resist scratching, while calcite will scratch easily. A streak test, magnification, and locality information would help separate quartz, quartzite, and chert.