mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

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

Identified April 6, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the cooling and crystallization of silica-rich hydrothermal fluids in veins or as a primary mineral in igneous rocks like granite. The 'milky' appearance is caused by tiny bubbles of gas or liquid trapped during crystal growth.

Uses & applications

Used as an abrasive, in glassmaking, as a gemstone (tumbled or cabochon), and as a source of silica for semiconductors and electronic components.

Geological facts

Milky quartz is the most common variety of crystalline quartz. While often overlooked by gem hunters, large milky quartz veins can be indicators of nearby gold deposits, a relationship known by prospectors for centuries.

Field identification & locations

Identify by its hardness (will scratch glass easily), lack of cleavage, and characteristic waxy or milky white appearance. It is found globally in almost all geological environments, particularly in mountainous regions and riverbeds.