mineral

Milky Quartz

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 May 16, 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 through the cooling of silica-rich magma or from hydrothermal veins. The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth. Can be found in various geological ages.

Uses & applications

Used in glassmaking, abrasives, electronics (piezoelectric properties), and as decorative stone or landscaping material. Low-grade specimens are common for beginner collectors.

Geological facts

Milky quartz is the most common variety of crystalline quartz. Its white color is often due to microscopic fluid inclusions that scatter light, similar to how clouds appear white in the sky.

Field identification & locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and white opaque appearance. Frequently found in mountain ranges, riverbeds, and as veins within other rock types like granite or schist.