mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale; Color: Cloudy white to grayish; Luster: Vitreous to greasy; Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: Cloudy white to grayish
Luster: Vitreous to greasy

Identified March 11, 2026More mineral →

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Physical properties

Hardness: 7 on the Mohs scale; Color: Cloudy white to grayish; Luster: Vitreous to greasy; Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal fluids in veins or as a primary constituent in igneous and metamorphic rocks. The cloudy appearance is caused by tiny liquid or gas inclusions trapped during crystal growth. Common throughout all geological eras.

Uses & applications

Used in the industry for glassmaking, abrasives, and as a source of silicon for electronics. In jewelry, it is often used for beads, cabochons, and decorative carvings. It is a staple for mineral collectors due to its abundance and variety.

Geological facts

Milky quartz is the most common variety of crystalline quartz. While transparent quartz is more sought after for gems, milky quartz can contain traces of gold, making it a primary target for gold prospectors.

Field identification & locations

Identify it by its white, 'milky' opacity and its ability to scratch glass easily. It is found globally in mountains, riverbeds, and as common garden stone. If it lacks visible crystal facets, it is often referred to as 'bull quartz' in the field.