mineral

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Colorless to white with reddish-brown iron oxide staining
Luster: Vitreous to greasy

Identified June 15, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes where silica-rich fluids cooled in veins or cavities within host rocks. Iron staining occurs from subsequent exposure to oxygen and water-containing iron oxides.

Uses & applications

Used in the production of glass, ceramics, and abrasives. Large, high-purity specimens are used in electronics and watches for their piezoelectric properties.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. 'Milky' quartz gets its white appearance from minute fluid inclusions trapped during crystal growth.

Field identification & locations

Identify by its hardness (it will scratch glass), lack of cleavage, and typical glassy luster. Often found in mountainous regions or inside vugs in metamorphic and igneous rocks.

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Mineral/Rock

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mineral