mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

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

Hardness: 7 on Mohs scale
Color: Cloudy white to opaque
Luster: Vitreous (glassy) to greasy

Identified April 7, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Cloudy white to opaque; Luster: Vitreous (glassy) 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 fluids in veins or as a primary constituent in igneous rocks like granite. The 'milky' appearance is caused by tiny inclusions of liquid or gas trapped during crystal growth.

Uses & applications

Used in the production of glass, ceramics, and electronics (due to piezoelectric properties). It is also popular for lapidary work, landscaping, and as a common specimen for beginner collectors.

Geological facts

Milky quartz is the most common variety of crystalline quartz. While it lacks the transparency of rock crystal, large masses can form enormous vein deposits that stretch for miles.

Field identification & locations

Identify in the field by its distinct white color, inability to be scratched by a steel knife (hardness), and lack of cleavage (it breaks in curved, shell-like patterns). It is found globally in almost all geological environments.