sedimentary

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: transclucent grey and tan with white inclusions, Luster: vitreous to waxy (weathered), Structure: microcrystalline quartz (chalcedony/chert variant)

Identified July 6, 2026More sedimentary →

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Physical properties

Hardness: 7 (Mohs scale), Color: transclucent grey and tan with white inclusions, Luster: vitreous to waxy (weathered), Structure: microcrystalline quartz (chalcedony/chert variant)

Formation & geological history

Formed through sedimentary processes or as a weathered fragment of a larger quartz vein; smoothed and rounded by the action of water in a river, beach, or glacial environment.

Uses & applications

Commonly used as decorative gravel, in landscaping, and as a component in construction aggregate. Smooth stones are also used in meditation or as worry stones.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. These rounded smooth shapes are a result of 'attrition,' where rocks collide and wear each other down during water transport.

Field identification & locations

Identify by its hardness (it will scratch glass) and its smooth, water-worn texture. Commonly found in riverbeds, stream banks, and coastal beaches worldwide.