mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Identified March 8, 2026More mineral →

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Physical properties

Hardness: 7 on 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 through the cooling of silica-rich magma or from hydrothermal veins. The white 'milky' appearance is caused by microscopic fluid inclusions of gas or liquid trapped during crystal growth. They are found in all geological ages.

Uses & applications

Used in glassmaking, abrasives, and as a source of silicon for semiconductors. In jewelry, it is often used for beads or cabochons. It is also used as decorative landscaping stone and in construction aggregates.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz is the most common variety of crystalline quartz. Historically, it was sometimes used by ancient cultures to create stone tools when flint was unavailable.

Field identification & locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and white opaque color. It is commonly found in mountain ranges, riverbeds, and as veins within granite or metamorphic rocks like schist.