mineral

Quartz (River Pebble)

Silicon Dioxide (SiO2)

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

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

Identified July 14, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed from silica-rich solutions in hydrothermal veins or as a primary constituent in igneous rocks. This specific specimen has been smoothed and rounded by water erosion in a fluvial (river) environment, likely originating from the Holocene age.

Uses & applications

Used widely in landscape gardening, aquarium decor, and construction aggregate. Pure quartz is vital in glass manufacturing and electronics.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the Greek word 'krustallos', meaning ice, as ancient Greeks believed it was ice that had frozen so hard it would never melt.

Field identification & locations

Identify by its hardness (it will easily scratch glass) and lack of cleavage planes. Found globally in riverbeds, beaches, and mountainous regions. For collectors, it is a staple foundational mineral.