mineral

Milky Quartz (with Iron Oxide staining)

Quartz (Silicon Dioxide - SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent with yellow/brown iron staining; Luster: Vitreous (glassy) to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to translucent with yellow/brown iron staining
Luster: Vitreous (glassy) to greasy

Identified March 26, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. This specimen likely formed in a hydrothermal environment where hot, mineral-rich water filled rock fractures. Quartz can be found in rocks from virtually every geological age, from Precambrian to recent.

Uses & applications

Industrial uses include glassmaking, abrasives, and electronics (due to piezoelectric properties). In crushed form, it is used for construction. It is also popular for lapidary work, decorative landscaping, and crystal collecting.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The 'milky' appearance is caused by tiny fluid inclusions of gas or liquid trapped during crystal growth. The yellow-orange tint on the surface is likely limonite or goethite staining.

Field identification & locations

Identify in the field by its hardness (it will scratch glass and steel), lack of cleavage, and glassy luster. It is commonly found in mountain ranges, riverbeds, and as veins within granite or metamorphic rocks like schist and gneiss.

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