mineral

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: White to opaque (milky) due to fluid inclusions; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: White to opaque (milky) due to fluid inclusions
Luster: Vitreous to greasy

Identified March 29, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the crystallization of molten magma or from hydrothermal veins. It is found in all geological ages and environments, often crystallizing as the last mineral in igneous cooling or as a precipitate from hot water solutions.

Uses & applications

Used in the manufacturing of glass, electronics (oscillators), abrasives, and as a stabilizer in construction. Lower grade milky specimens are often used for landscaping or as a base material for crushed stone.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is clear, but milky quartz gets its name from millions of microscopic fluid inclusions of gas or liquid trapped during crystal growth.

Field identification & locations

Identify in the field by its ability to scratch glass (hardness 7) and its lack of cleavage. It is commonly found in gravel pits, mountain streams, and within granite outcrops globally. For collectors, look for well-defined crystal faces or points.