mineral

Milky 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 March 14, 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 from the crystallization of silica-rich magma or precipitation from hydrothermal fluids in veins and geodes. It can be found in a wide variety of geological environments and ages, from Precambrian to recent.

Uses & applications

Major source of silicon for semiconductors and glass manufacturing. Also used as a gemstone (low value), in construction as an abrasive, and in landscaping or as collector's specimens.

Geological facts

Milky quartz gets its cloudy appearance from tiny fluid inclusions of gas or liquid trapped during crystal growth. It is the most common variety of crystalline quartz on Earth.

Field identification & locations

Identify by its white color, ability to scratch glass (hardness 7), and lack of cleavage planes. It is often found in mountain ranges, riverbeds, and as veins in igneous or metamorphic rocks worldwide.