mineral

Quartz (specifically Milky or Iron-stained Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Translucent white to tan/yellow (due to iron inclusions); Luster: Vitreous (glassy) to waxy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Translucent white to tan/yellow (due to iron inclusions)
Luster: Vitreous (glassy) to waxy

Identified April 3, 2026More mineral →

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Physical properties

Formation & geological history

Formed from hydrothermal veins or cooling magma. This particular specimen appears to be a water-worn or tumbled pebble, likely weathered out of its host rock and rounded by transport in a river or coastal environment.

Uses & applications

Used widely in glassmaking, electronics (piezoelectric properties), abrasives, and as a popular gemstone or decorative garden stone.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'quarz', which has Slavic origins meaning 'hard'.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife (hardness 7) and its lack of cleavage. It is extremely common in gravel pits, riverbeds, and mountainous regions worldwide.

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