mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 Mohs; Color: Milky white to opaque; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 Mohs
Color: Milky white to opaque
Luster: Vitreous to greasy

Identified June 29, 2026More mineral →

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Physical properties

Hardness: 7 Mohs; Color: Milky white to opaque; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Forms through the hydrothermal crystallization of silica-rich fluids in veins or as a late-stage mineral in igneous intrusions like pegmatites. The white color is caused by tiny inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used frequently in clock and watch manufacturing (due to piezoelectric properties), glassmaking, electronics, and as a decorative stone in jewelry or landscaping.

Geological facts

Milky quartz is one of the most common minerals on Earth. Its opacity is due to microscopic 'fluid inclusions' trapped at the time of the crystal's formation millions of years ago.

Field identification & locations

Identify in the field by its hardness (will scratch glass), white color, and the way it breaks into curved, shell-like surfaces (conchoidal fracture). It is found globally across all continents in mountainous and rocky terrains.