mineral

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Hardness: 7 on the Mohs scale. Color: White to cloudy translucent. Luster: Vitreous to greasy. Crystal Structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: White to cloudy translucent
Luster: Vitreous to greasy

Identified April 3, 2026More mineral →

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Physical properties

Hardness: 7 on the Mohs scale. Color: White to cloudy translucent. Luster: Vitreous to greasy. Crystal Structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Formation & geological history

Formed from the crystallization of silica-rich hydrothermal fluids in veins or from cooling magma. Milky quartz gets its appearance from tiny fluid or gas inclusions trapped during crystal growth. They can be found in igenous, metamorphic, and sedimentary environments across all geological ages.

Uses & applications

Used as a gemstone (cabochons), in glassmaking, as an abrasive, in the production of silicon chips, and as landscape stone.

Geological facts

Milky quartz is the most common variety of crystalline quartz. Its white 'milkiness' is caused by millions of microscopic bubbles of liquids or gases that were trapped when the crystal was forming.

Field identification & locations

Identify in the field by its ability to scratch glass (hardness 7), its lack of cleavage, and its characteristic waxy or glassy luster. It is found globally in mountains, riverbeds, and beach sands.