mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: White to translucent with brown iron staining; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: White to translucent with brown iron staining
Luster: Vitreous to greasy

Identified March 4, 2026More mineral →

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Physical properties

Formation & geological history

Formed during the final stages of magma crystallization in pegmatites or from hydrothermal veins. Often found in metamorphic rocks and as a primary constituent of granites. Its milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used as a source of silicon for electronics, as an abrasive in sandblasting, in glassmaking, and in landscaping. Polished specimens are used in lapidary work and beads.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz specifically gets its color from fluid inclusions that were trapped several billion to several million years ago during formation.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), its lack of cleavage, and its waxy or vitreous luster. It is common worldwide in mountain ranges and riverbeds. Collectors should look for iron-stained 'gold quartz' which can sometimes indicate nearby gold deposits.