mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White, translucent, or milky; Luster: Vitreous to waxy; Crystal structure: Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

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

Identified July 6, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White, translucent, or milky; Luster: Vitreous to waxy; Crystal structure: Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Formation & geological history

Formed through the cooling of silica-rich magma or precipitation from hydrothermal fluids. This specimen is a water-worn, rounded pebble likely eroded from a larger vein and smoothed by fluvial or coastal transport over thousands of years.

Uses & applications

Used in the production of glass, ceramics, and abrasives. In this rounded form, they are often used in decorative landscaping, aquarium substrate, or as river stones for massage therapy.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. When found in riverbeds, their smooth, 'frosted' surface is caused by thousands of tiny impacts against other rocks during transport.

Field identification & locations

Identify by its hardness (will scratch glass) and lack of cleavage. Look for a waxy or greasy surface on rounded pebbles. Common in riverbeds, beaches, and glacial till globally.