mineral

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Opaque white to yellowish-brown (due to iron oxidation); Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Opaque white to yellowish-brown (due to iron oxidation)
Luster: Vitreous to greasy

Identified April 26, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes or within igneous pegmatites. It crystallizes from silica-rich fluids in veins or cavities within the Earth's crust across all geological ages.

Uses & applications

Used in glass making, electronics (piezoelectric properties), abrasives, and as a component in construction materials like concrete and mortar. Common as a filler in paints and rubber.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is clear, but 'Milky Quartz' gets its cloudy look from tiny fluid inclusions trapped during crystal growth.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), lack of cleavage, and waxy/vitreous luster. Found globally, often in mountain ranges and riverbeds.

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Mineral/Rock

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