mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Identified July 14, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to opaque; 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 or magma. The white color is caused by tiny bubbles of gas or liquid trapped during crystal growth. They are found in igneous, metamorphic, and sedimentary environments.

Uses & applications

Used in glassmaking, abrasives, silicon production, and as a decorative stone. High-quality specimens are used in electronics for their piezoelectric properties.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz is the most common variety of quartz. Its white opacity is due to microscopic inclusions of fluids that have been trapped since the time the crystal first grew.

Field identification & locations

Identify by its hardness (it will scratch glass), lack of cleavage, and white opaque appearance. It is found globally, often occurring in large veins that resist weathering and stand out against surrounding rock.