mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: White to off-white/tan due to 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 off-white/tan due to iron staining
Luster: Vitreous to greasy

Identified July 12, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth. Can be found in various geological ages globally.

Uses & applications

Used in glass making, abrasive materials, electronics (as a source of silicon), and as decorative landscaping stone. Lower grade specimens are used in construction aggregates.

Geological facts

Milky quartz is the most common variety of crystalline quartz. The white color is often attributed to microscopic fluid inclusions that scatter light, creating an opaque appearance.

Field identification & locations

Identify by its ability to scratch glass and lack of cleavage. It is extremely common in mountainous regions, riverbeds, and as veins within igneous and metamorphic rocks. Collectors look for pieces with interesting iron staining or crystal terminations.