mineral

Iron-stained Milky Quartz

Silicon Dioxide (SiO2) with iron oxide inclusions

Hardness: 7 (Mohs scale), Color: White to yellowish-orange due to staining, Luster: Vitreous to greasy, Crystal structure: Hexagonal/Trigonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified April 5, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal fluids in veins or as a late-stage crystallization in igneous rocks. The yellow staining is secondary, caused by the weathering of iron-rich minerals that leach limonite or goethite into fractures.

Uses & applications

Used as a common specimen for collectors, in landscaping (river rock), as a source of silica for glass manufacturing, and sometimes as a decorative stone or in tumbled jewelry.

Geological facts

Milky quartz gets its cloudy appearance from minute fluid inclusions of gas or liquid trapped during crystal growth. Iron-stained varieties can often be cleaned with mild acids (like oxalic acid) to return them to a white color.

Field identification & locations

Identify by its ability to scratch glass, its lack of cleavage, and the uneven yellowish staining on the surface or in cracks. Commonly found in riverbeds, mountains, and near volcanic regions worldwide.

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