mineral

Milky Quartz (or Bull Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: White to off-white with yellowish staining from iron oxidation; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Luster: Vitreous to greasy

Identified March 29, 2026More mineral →

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Physical properties

Formation & geological history

Formed from the crystallization of silica-rich hydrothermal fluids in veins or pegmatites. The milky appearance is caused by microscopic fluid inclusions of gas or liquid trapped during crystal growth. They can range from millions to billions of years old.

Uses & applications

Used in the production of glass, ceramics, and silicone. Historically used for making stone tools. Often used as decorative landscaping stone or in jewelry (as cabochons) when it contains gold or unique inclusions.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz is often the 'vein' material that miners follow when searching for gold, as the two often form in the same hydrothermal environments.

Field identification & locations

Identify in the field by its ability to scratch glass, its lack of cleavage (it breaks in irregular or curved 'conchoidal' shards), and its snowy/waxy white color. Found globally, especially in mountainous or volcanic regions. Collectors look for pieces with iron staining (shown in the image) or internal rainbows.

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