mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: White to off-white with tan/iron oxide staining. Luster: Vitreous to greasy. Crystal structure: Hexagonal/Trigonal. Cleavage: None (conchoidal fracture). Specific gravity: ~2.65.

Hardness: 7 on Mohs scale
Color: White to off-white with tan/iron oxide staining
Luster: Vitreous to greasy

Identified July 25, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins, pegmatites, and metamorphic rocks. Bubbles of microscopic gas or liquid trapped during crystal growth give it its characteristic cloudy or milky white appearance.

Uses & applications

Used in gemstone collections, landscape design, construction aggregate, and as a source of silicon for semiconductor and solar panel production.

Geological facts

Milky quartz is the most common variety of crystalline quartz found on Earth's surface. The milky white color is caused by minute fluid inclusions trapped during the mineral's formation millions of years ago.

Field identification & locations

Identified in the field by its hardness (scratches glass, cannot be scratched by a steel knife), lack of cleavage, and milky white translucent appearance often with brownish iron-staining in crevices. Found in abundance worldwide in riverbeds, gravel pits, and mountainous regions.