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 March 18, 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 through the cooling of silica-rich hydrothermal veins or magma in igneous and metamorphic environments. The white color is caused by minute fluid inclusions of gas and/or liquid trapped during crystal growth. Can be found in rocks from almost any geological age.

Uses & applications

Used in glassmaking, abrasives, and as a source of silicon for electronics. In the gemstone trade, it's used for cabochons, carvings, and landscape decoration. Historically used for making stone tools.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz specifically is common because the 'milkiness' is the result of 'bubbles' trapped during formation, which can be millions per square millimeter.

Field identification & locations

Identify by its hardness (it will scratch glass), lack of cleavage, and characteristic waxy-to-glassy luster. It is commonly found in riverbeds, mountain outcrops, and as pebbles in soil. Look for the white, cloudy appearance and resistance to weathering.