mineral

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Opaque white (milky) with reddish-orange iron oxide staining; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Opaque white (milky) with reddish-orange iron oxide staining
Luster: Vitreous to waxy

Identified March 26, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal fluids cooling in igneous or metamorphic veins. The milky appearance is caused by microscopic fluid inclusions trapped during rapid crystallization. The variety of ages can span from millions to billions of years depending on the host rock environment.

Uses & applications

Used widely in glassmaking, as an abrasive, and in electronics due to piezoelectric properties. In this tumbled form, it is common in the gemstone market for jewelry, metaphysical 'healing' stones, and home decor.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The 'milky' look is actually due to millions of tiny bubbles of gas or liquid trapped inside the crystal as it grew.

Field identification & locations

Identify in the field by its inability to be scratched by a steel pocket knife and its lack of cleavage. It is ubiquitous globally and frequently found in riverbeds and mountainous terrain. Collectors should look for unique internal patterns or iron-rich swirls.

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