mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky to translucent off-white/beige; Luster: Vitreous to waxy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: ~2.65

Hardness: 7 on Mohs scale
Color: Milky to translucent off-white/beige
Luster: Vitreous to waxy

Identified July 22, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky to translucent off-white/beige; Luster: Vitreous to waxy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: ~2.65

Formation & geological history

Formed through igneous activity in pegmatites or hydrothermal veins, then eroded, transported by water, and rounded into a river or beach pebble over thousands to millions of years.

Uses & applications

Used in lapidary work, tumbled stones, landscaping, aggregate production, and silica source for industrial glass and electronics manufacture.

Geological facts

Quartz is one of the most abundant minerals in Earth's continental crust. Its high hardness and lack of cleavage allow it to resist chemical and physical weathering extremely well, allowing smooth pebbles like this to form in stream beds and coastal waters.

Field identification & locations

Identify by its hardness (scratches glass easily), smooth river-worn texture, waxy-to-glassy luster, and light transmittance when held to a bright light. Very common along gravel bars, beaches, and riverbeds worldwide.