mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Opaque white; Luster: Vitreous to greasy; Crystal Structure: Trigonal (hexagonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

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

Identified April 13, 2026More mineral →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 7 on Mohs scale; Color: Opaque white; Luster: Vitreous to greasy; Crystal Structure: Trigonal (hexagonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Formed from silica-rich hydrothermal fluids or solidifying magma. Its white color comes from minute fluid inclusions of gas and/or liquid trapped during crystal growth.

Uses & applications

Used as a primary source of silicon, in glass manufacturing, as a decorative gemstone, and broadly in landscaping and construction.

Geological facts

Milky quartz is the most common variety of crystalline quartz. Historically, it was used by many cultures for tool making due to its high hardness and sharp fracture edges.

Field identification & locations

Identify in the field by its hardness (scratches glass), waxy or vitreous luster, and lack of cleavage. It is found globally in igneous and metamorphic terrains.