mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Milky white to translucent
Luster: Vitreous to greasy

Identified April 30, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed from silica-rich hydrothermal fluids cooling in veins and cavities within igneous, metamorphic, and sedimentary rocks. Its cloudy white color is caused by microscopic fluid inclusions trapped during growth.

Uses & applications

Used as a source of silicon for semiconductors, manufacturing of glass and ceramics, as an abrasive, in construction as aggregate, and frequently used in lapidary for decorative stones.

Geological facts

Milky Quartz is one of the most common varieties of crystalline quartz on Earth. The white opacity is due to tiny bubbles of gas or liquid that were trapped when the crystal was forming millions of years ago.

Field identification & locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and white 'milky' appearance. It is found globally, particularly in mountainous regions and riverbeds.