mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to tan; Luster: Vitreous to waxy; Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to tan
Luster: Vitreous to waxy

Identified July 11, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to tan; Luster: Vitreous to waxy; Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Formation & geological history

Formed from hydrothermal veins or as a primary constituent in igneous rocks like granite. This specimen has been rounded and smoothed by water erosion (alluvial/fluvial processes) over thousands of years.

Uses & applications

Used in glass making, electronics (piezoelectric properties), abrasives, and as decorative landscaping stone. High-purity quartz is a source of silicon for computer chips.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is highly resistant to chemical and physical weathering, which is why it often remains as rounded pebbles long after other minerals have eroded.

Field identification & locations

Identified by its ability to scratch glass and steel, its lack of cleavage, and its smooth, water-worn texture. Commonly found in riverbeds, beaches, and glacial deposits worldwide.