mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

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

Hardness: 7 on Mohs scale
Color: Cloudy white to opaque
Luster: Vitreous (glassy) to greasy

Identified March 8, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the cooling of magma or by hydrothermal precipitation from hot fluids in veins. The white color is caused by microscopic inclusions of gas or liquid trapped during crystal growth. They are found in all geological ages.

Uses & applications

Used in glassmaking, abrasives, and as a source of silicon for electronics. In jewelry, it is often used for beads, cabochons, or ornamental carvings. It is also a very common specimen for beginner rock collectors.

Geological facts

Milky quartz is the most common variety of crystalline quartz. It can often be found in 'veins' that cut through other rock types, and it is frequently associated with gold deposits in 'mother lode' style formations.

Field identification & locations

Identify in the field by its white color, ability to scratch glass (hardness 7), and lack of cleavage. It is found globally, often eroding out of hillsides or in stream beds. Collectors should look for points or large, clean fractures.