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 prisms); 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 15, 2026More mineral →

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Physical properties

Formation & geological history

Forms in igneous, metamorphic, and sedimentary environments through the cooling of silica-rich magma or precipitation from hydrothermal fluids. Its cloudiness is caused by microscopic fluid inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in the glass and ceramics industry, as a flux in metallurgy, and as decorative gravel. Lower quality pieces are used for abrasive purposes, while clearer specimens are used in jewelry and lapidary art.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz is the most common variety of quartz. It can often be found in large veins that may contain gold or other precious metals.

Field identification & locations

Identify in the field by its ability to scratch glass (hardness 7), lack of cleavage, and characteristic cloudy white Appearance. It is found globally, notably in the Appalachian Mountains, Urals, and Alps. Collectors look for sharp crystal faces or inclusions of other minerals.