mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Hardness: 7 on the Mohs scale
Color: Opaque white to translucent
Luster: Vitreous to greasy

Identified March 21, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed from the cooling of silica-rich hydrothermal fluids in veins or as a primary constituent of igneous rocks like granite. Its white color is caused by microscopic fluid inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in the production of glass and ceramics, as an abrasive, in the semiconductor industry (silicon source), and as landscape stone or decorative gravel.

Geological facts

Milky Quartz is the most common variety of crystalline quartz. While it lacks the clarity of Rock Crystal, it is chemically identical. Large veins of it can often contain trace amounts of gold, making it a primary target for prospectors.

Field identification & locations

Identify in the field by its ability to scratch glass, its milky waxy appearance, and its lack of cleavage. Commonly found in riverbeds, mountain ranges, and gravel pits globally. Collectors should look for sharp crystal faces or interesting inclusions.