mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7.0 on Mohs scale; Color: Opaque white to translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7
Color: Opaque white to translucent
Luster: Vitreous to greasy

Identified June 26, 2026More mineral →

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Physical properties

Hardness: 7.0 on Mohs scale; Color: Opaque white to translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal fluids in veins or as a common constituent of igneous rocks like granite. The white color comes from microscopic fluid inclusions trapped during growth.

Uses & applications

Used in glass manufacturing, as a source for silicon, in construction as decorative aggregate, and in landscaping or jewelry (cabochons).

Geological facts

Milky quartz is the most common variety of crystalline quartz. Historically, it was used by many cultures for stone tools when flint was unavailable.

Field identification & locations

Identify by its ability to scratch glass, its milky white appearance, and lack of cleavage. It is found globally, particularly in mountainous regions and riverbeds.