Mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

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

Identified March 16, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed from the crystallization of silica-rich hydrothermal fluids in veins or as a late-stage mineral in igneous pegmatites. It derives its white color from microscopic inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used widely as an abrasive, in the production of glass and ceramics, as a source of silicon for electronics, and in landscaping or as a gemstone for carving and jewelry.

Geological facts

Milky quartz is the most common variety of crystalline quartz. Historically, it was used by many cultures to produce stone tools before the advent of metalworking due to its hardness and ability to hold a sharp edge when fractured.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife (it will scratch glass instead) and its lack of cleavage planes. It is found globally in almost all geological environments including mountains, riverbeds, and beaches.