sedimentary

Quartz Pebble

Silicon Dioxide (SiO2)

Mohs hardness of 7; dull to waxy/vitreous luster; trigonal crystal system; pale off-white to grayish color; no cleavage; smooth, water-worn sub-rounded pebble shape.

Identified July 25, 2026More sedimentary →

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Physical properties

Mohs hardness of 7; dull to waxy/vitreous luster; trigonal crystal system; pale off-white to grayish color; no cleavage; smooth, water-worn sub-rounded pebble shape.

Formation & geological history

Formed through mechanical weathering and stream erosion of silica-rich vein quartz or quartzite rock, resulting in a smooth beach or river pebble.

Uses & applications

Used as decorative landscaping stone, in aquariums, or as raw material for aggregate and mineral collecting.

Geological facts

Quartz pebbles are among the most durable rocks on Earth's surface due to quartz's high hardness and resistance to chemical weathering.

Field identification & locations

Identified by its hard surface (scratches glass readily), smooth rounded texture, lack of cleavage, and light neutral color. Extremely common along riverbeds and ocean beaches worldwide.