mineral

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Opaque white with brown/yellow oxidation; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Opaque white with brown/yellow oxidation
Luster: Vitreous to greasy

Identified April 14, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes or igneous crystallization in pegmatites and veins. The fractures and brown staining are caused by secondary iron oxide infiltration (limonite/hematite) after the quartz formed.

Uses & applications

Used in glass manufacturing, electronics (piezoelectric properties), abrasives, and as a common gemstone/collectible.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Specimens like this one, showing a 'lattice' of iron staining, are often found in areas with high mineral weathering.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), lack of cleavage, and characteristic waxy or glassy appearance. It is ubiquitous in mountainous and riverbed environments.

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Mineral/Rock

Banded Gneiss (River Rock/Pebble)

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Metamorphic Rock

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mineral