mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White, translucent, or cloudy; Luster: Vitreous to waxy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White, translucent, or cloudy
Luster: Vitreous to waxy

Identified June 14, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White, translucent, or cloudy; Luster: Vitreous to waxy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed from cooling magma or precipitation in hydrothermal veins. This specifically is a water-worn river pebble, likely transported and smoothed by alluvial processes over thousands of years.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, and as decorative gravel. Tumbled stones are used in jewelry and lapidary arts.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is known as rock crystal, while cloudy variations like this are often called milky quartz.

Field identification & locations

Identified by its hardness (it can scratch glass and steel) and lack of cleavage planes. Commonly found in riverbeds, beaches, and soil worldwide. It is a primary constituent of granitic rocks.