mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to tan; Luster: Vitreous to waxy (when river-worn); Crystal structure: Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to tan
Luster: Vitreous to waxy (when river-worn)

Identified June 2, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to tan; Luster: Vitreous to waxy (when river-worn); Crystal structure: Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. This specific specimen is likely a water-worn river pebble, shaped by erosion and transport over thousands of years.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, and as decorative gravel or landscaping stone.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is colorless, but impurities create varieties like amethyst, citrine, and rose quartz.

Field identification & locations

Identify in the field by its hardness (it can scratch glass), lack of cleavage, and rounded shape if found near water. Extremely common in riverbeds and mountainous terrain worldwide.