mineral

Milky Quartz with Iron Inclusions

Crystalline Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Cloudy white to tan with brownish-red iron staining; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Cloudy white to tan with brownish-red iron staining
Luster: Vitreous to greasy

Identified June 27, 2026More mineral →

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Physical properties

Formation & geological history

Formed from hydrothermal veins cooling within the Earth's crust. It often forms as large masses rather than distinct crystals. Iron-rich groundwater has permeated micro-fractures in this specimen, creating the reddish-brown staining.

Uses & applications

Used in glassmaking, abrasives, and as a component in computer chips. Coarse specimens like this are often used in landscaping or as decorative garden stones. High-quality pieces are used for lapidary work.

Geological facts

Quartz is the most abundant mineral in Earth's crust. Milky quartz gets its opaque white color from tiny fluid or gas bubbles trapped within the crystal lattice during growth.

Field identification & locations

Identify by its hardness (it will scratch glass), lack of cleavage, and waxy luster when wet. It is commonly found in riverbeds, glacial tills, and as veins in metamorphic terrains worldwide.

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mineral