mineral

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White to translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White to translucent
Luster: Vitreous to greasy

Identified April 3, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White to translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. It is found in a wide variety of geological environments including igneous, metamorphic, and sedimentary settings across all geological ages.

Uses & applications

Used in glassmaking, abrasives, foundry sand, hydraulic fracturing proppant, and as a component in electronics (due to piezoelectric properties). Low-grade milky quartz is often used in landscaping or construction aggregate.

Geological facts

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

Field identification & locations

Identify in the field by its ability to scratch glass, its lack of cleavage, and its waxy/glassy luster. It is highly resistant to weathering and often found as rounded pebbles in riverbeds or on beaches.