mineral

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: White to translucent with yellowish-brown iron oxide staining; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Luster: Vitreous to greasy

Identified May 12, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal solutions in veins or as a primary constituent of igneous rocks like granite. The iron staining occurs post-crystallization due to weathering and oxidation of iron-bearing minerals.

Uses & applications

Industrial use in glassmaking, abrasives, and electronics (piezoelectric properties). Massive milky quartz is used in construction as aggregate or decorative landscaping stone.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is clear, but tiny fluid or gas inclusions trapped during crystal growth create the 'milky' white appearance.

Field identification & locations

Identify by its hardness (scratches glass), lack of cleavage, and waxy to vitreous luster. It is ubiquitous globally, especially in mountain ranges and riverbeds. Look for rusty patches which indicate iron oxidation.

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