mineral

Quartz (specifically Milky Quartz Pebble)

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale. Color: Translucent white to milky white. Luster: Vitreous to greasy. Crystal Structure: Hexagonal (trigonal habit). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: Translucent white to milky white
Luster: Vitreous to greasy

Identified March 30, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of silica-rich magma or precipitation from hydrothermal veins. This specific specimen appears to be water-worn (a pebble), suggesting it was eroded from its primary vein and transported by a river or stream over thousands of years.

Uses & applications

Quartz is used in glassmaking, electronics (piezoelectric properties), abrasives, and as a gemstone (tumbled stones). White quartz pebbles are also common for landscaping.

Geological facts

Quartz is the second most abundant mineral in the Earth's continental crust. The 'milky' appearance is caused by tiny inclusions of gas and/or liquid trapped during the crystal's growth.

Field identification & locations

Identify in the field by its hardness (it will scratch glass and cannot be scratched by a steel knife) and lack of cleavage (it breaks into irregular, glass-like shards). Commonly found in riverbeds, beaches, and mountain trails worldwide.

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