mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

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

Hardness: 7 on Mohs scale
Color: Cloudy white to grayish
Luster: Vitreous to greasy

Identified April 27, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Cloudy white to grayish; 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 hydrothermal veins or magma in igneous intrusions like granite and pegmatite. The white 'milky' appearance is caused by microscopic inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used as a source of silicon for electronics, as an abrasive in sandblasting, in glassmaking, as a decorative garden stone, and as a pocket stone for collectors.

Geological facts

Quartz is one of the most abundant minerals in Earth's crust. Milky quartz specifically gets its opacity from billions of tiny fluid inclusions that scatter light.

Field identification & locations

Identify in the field by its ability to scratch glass (hardness 7), lack of cleavage, and white 'icy' appearance. It is often found in veins cutting through other rock types. It is found globally, notably in the Appalachian Mountains and the Alps.