mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

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

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

Identified March 29, 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: Hexagonal/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 primary constituent in igneous rocks like granite. The 'milky' appearance is caused by microscopic inclusions of fluids or gas trapped during crystal growth.

Uses & applications

Used as a source of silica for glassmaking, abrasives, and electronics. Common in landscaping, construction aggregate, and as a semi-precious stone in jewelry or 'healing' crystals.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz is often found in gold-bearing veins, leading old-time miners to refer to it as 'veta madre' (mother vein).

Field identification & locations

Identify in the field by its hardness (it will scratch glass), lack of cleavage, and white cloudy appearance. It is found globally, particularly in mountainous regions and riverbeds as rounded pebbles.