mineral

Milky Quartz (Ferruginous variety)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to tan/peach (due to iron stains); Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to tan/peach (due to iron stains)
Luster: Vitreous to greasy

Identified March 13, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal solutions in veins or pegmatites; found in igneous, metamorphic, and sedimentary environments globally throughout all geological ages.

Uses & applications

Used in manufacturing glass and ceramics, as an abrasive in sandpaper, in its purest form for electronics/oscillators, and as decorative gravel or landscaping stone.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The tan/orange hue in this specimen is caused by tiny inclusions of iron oxides or 'rust' staining the surfaces and cracks.

Field identification & locations

Identify by its hardness (it will easily scratch glass) and lack of cleavage. Common in river beds, mountain trails, and garden fill. Collectors look for clear terminations or unique crystal clusters.

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