mineral

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to opaque; Luster: Vitreous to greasy; Crystal Structure: Trigonal (hexagonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to opaque
Luster: Vitreous to greasy

Identified April 29, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to opaque; Luster: Vitreous to greasy; Crystal Structure: Trigonal (hexagonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins, pegmatites, and as a primary constituent of igneous and metamorphic rocks. The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in glassmaking, abrasives, silicon production, electronics (piezoelectric properties), and as decorative stone or landscaping gravel.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz is the most common variety of crystalline quartz found in nature.

Field identification & locations

Identify in the field by its hardness (it can scratch glass), lack of cleavage, and characteristic waxy or milky white appearance. It is ubiquitous in mountainous and riverbed environments.