mineral

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Hardness: 7.0 on Mohs scale; Color: Opaque white to cream; Luster: Vitreous to greasy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7
Color: Opaque white to cream
Luster: Vitreous to greasy

Identified March 18, 2026More mineral →

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Physical properties

Hardness: 7.0 on Mohs scale; Color: Opaque white to cream; Luster: Vitreous to greasy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal fluids in veins or as a primary constituent in igneous rocks. The milky appearance is caused by microscopic inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in the production of glass, ceramics, and abrasives. High-purity specimens are used in electronics for their piezoelectric properties. Common in landscaping and as a pocket stone for collectors.

Geological facts

Milky quartz is the most common variety of crystalline quartz. While it lacks the transparency of rock crystal, it is chemically identical and can be found on every continent, often forming massive veins that can span miles.

Field identification & locations

Identify in the field by its superior hardness (cannot be scratched by a steel knife) and its white, waxy appearance. It is frequently found in gravel pits, mountain streams, and within granite outcrops.