mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

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

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

Identified March 18, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal solutions in veins or as a major constituent of igneous rocks like granite. Its white color comes from minute fluid inclusions of gas and/or liquid trapped during crystal growth.

Uses & applications

Used in the glass and ceramics industry, as a gemstone (cabochons), as decorative landscaping stone, and in the production of silicon for electronics.

Geological facts

Milky quartz is the most common variety of crystalline quartz. Historically, it was often confused with white marble, but its extreme hardness allows it to scratch glass, which marble cannot do.

Field identification & locations

Identify in the field by its white, cloudy appearance and ability to scratch glass (hardness 7). It is found globally, often in mountain ranges and riverbeds where it erodes out of quartz veins.