Milky Quartz with Iron Staining

Physical Properties

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

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.

Identified on: 4/26/2026

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