mineral

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: White to creamy tan (stained by iron); Luster: Vitreous to greasy; Crystal Structure: Trigonal (hexagonal prisms); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: White to creamy tan (stained by iron)
Luster: Vitreous to greasy

Identified April 13, 2026More mineral →

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Physical properties

Formation & geological history

Formed from the cooling of silica-rich magma or from hydrothermal veins. This specific specimen is a water-worn river stone, likely millions of years old, smoothed by hydraulic action in a stream or beach environment.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, and as a decorative landscaping stone. High-purity quartz is vital for semiconductor manufacturing.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz gets its cloudiness from tiny inclusions of gas or liquid trapped during the crystal's growth.

Field identification & locations

Identify in the field by its ability to scratch glass, lack of cleavage, and waxy/vitreous luster. Common in mountains, riverbeds, and beaches worldwide.