mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Opaque white to creamy white
Luster: Vitreous to greasy

Identified March 22, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the cooling of silica-rich hydrothermal fluids in veins or as a late-stage mineral in igneous pegmatites. The white color is caused by microscopic fluid inclusions of gas or liquid trapped during crystal growth. Found in deposits ranging from Precambrian to recent geological ages.

Uses & applications

Used as a source of silicon for glassmaking and electronics, in construction as decorative aggregate, and as a semi-precious stone for lapidary work (cabochons and carvings). Also popular for landscaping and metaphysical collecting.

Geological facts

Milky quartz is the most common variety of crystalline quartz on Earth. The 'milkiness' is actually a cloud of millions of tiny bubbles of water or CO2 that scatter light within the crystal, a phenomenon similar to how water vapor creates a white cloud in the sky.

Field identification & locations

Identify in the field by its white color, inability to be scratched by a steel knife (hardness 7), and glass-like luster on fresh fractures. Commonly found in riverbeds, mountain outcrops, and as pebbles in soil. It is a key indicator of hydrothermal activity.