mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Milky white to translucent pinkish-tan; Luster: Vitreous to waxy (when water-worn); Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Milky white to translucent pinkish-tan
Luster: Vitreous to waxy (when water-worn)

Identified March 30, 2026More mineral →

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Physical properties

Formation & geological history

Formed from the crystallization of silica-rich hydrothermal fluids or cooling magma. This specific specimen is a 'river rock' or 'alluvial pebble,' meaning it has been weathered and rounded by the abrasive action of water (river or beach) over hundreds to thousands of years.

Uses & applications

Industrial use in glassmaking and abrasives; construction as aggregate; landscaping and decoration; used in jewelry as cabochons or tumbled stones.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Most sand on beaches around the world is composed primarily of tiny, weathered grains of quartz identical to this larger pebble.

Field identification & locations

Identify in the field by its hardness (it will scratch glass and metal) and its rounded, smooth texture indicating transport by water. It is found globally in riverbeds, beaches, and glacial deposits. For collectors, look for clarity or unique inclusions.