mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White to translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White to translucent
Luster: Vitreous to greasy

Identified March 24, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 7 (Mohs scale); Color: White to translucent; 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 solutions or magma. It is commonly found in veins or as a major constituent in granite and metamorphic rocks. Age ranges from billions of years to relatively recent formations.

Uses & applications

Used in glassmaking, abrasives, and as a raw material in the electronics industry for silicon chips. Also used in construction aggregate and occasionally as a base material for inexpensive jewelry or garden landscaping.

Geological facts

Milky quartz gets its cloudy white appearance from tiny inclusions of gas or liquid trapped during the crystal's growth. It is one of the most abundant minerals in the Earth's continental crust.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife (it will scratch glass). It typically lacks clear crystal faces unless found in a vug. Found globally in almost any environment containing igneous or metamorphic outcrops.