mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

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

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

Identified May 15, 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: Milky white to translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Forms in various geological environments, most commonly from hydrothermal veins or as a primary constituent in igneous rocks like granite. The milky appearance is caused by tiny fluid inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in glassmaking, abrasives, silicon production, and as a decorative stone in landscaping. High-quality quartz is used in electronics for its piezoelectric properties.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz specifically is white because of microscopic bubbles of water or carbon dioxide trapped within the crystal structure.

Field identification & locations

Identify in the field by its hardness (it can scratch glass), its white 'milky' color, and its lack of cleavage. It is extremely common worldwide and often found as 'river rocks' or vein material in mountainous regions.