mineral

Milky Quartz with Iron Inclusions

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Opaque white to cream with rusty brown/orange iron staining; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Opaque white to cream with rusty brown/orange iron staining
Luster: Vitreous to greasy

Identified March 3, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal fluids cooling in veins or pockets of igneous or metamorphic rock. The 'milky' appearance is caused by microscopic fluid inclusions trapped during the rapid growth of the crystals. Iron staining occurs through secondary weathering and oxidation.

Uses & applications

Used industrially as a source of silica for glass and ceramics, as an abrasive, and in construction as gravel. For collectors, it is valued for its raw natural appearance and use in lapidary work (cabochons and carvings).

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz is often found alongside gold in hydrothermal veins, leading old-time miners to call it 'bull quartz' or 'mother of gold.'

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife, its lack of cleavage, and its characteristic milky-white opacity. Commonly found in mountain ranges, river beds, and eroded outcrops worldwide.

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