mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale (scratches glass). Color: Opaque white to translucent. Luster: Vitreous (glassy) to greasy. Crystal structure: Hexagonal/Trigonal. Cleavage: Indistinct/Conchoidal fracture. Specific gravity: 2.65.

Hardness: 7 on Mohs scale (scratches glass)
Color: Opaque white to translucent
Luster: Vitreous (glassy) to greasy

Identified March 29, 2026More mineral →

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Physical properties

Formation & geological history

Formed from the crystallization of silica-rich molten rock (magma) or from hydrothermal veins. The white 'milky' color is caused by microscopic inclusions of gas or liquid trapped during crystal growth. They are found in all geological ages from Precambrian to recent.

Uses & applications

Used in glass making, abrasive manufacturing, electronics (due to piezoelectric properties), construction aggregates, and as decorative landscape stone or tumbled 'river rocks'.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz specifically is the most common variety of quartz. Its opacity is due to millions of tiny fluid inclusions that scatter light.

Field identification & locations

Identify in the field by its white color, ability to scratch glass, and lack of reaction to acid. It is commonly found in riverbeds, mountain outcrops, and as pebbles in soil. Collectors look for pieces with interesting shapes or translucency.