mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: White to milky white, often stained orange/brown by iron oxides. Luster: Vitreous to greasy. Crystal structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Luster: Vitreous to greasy

Identified May 10, 2026More mineral →

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Physical properties

Formation & geological history

Formed from the crystallization of silica-rich hydrothermal fluids in veins or as a late-stage mineral in igneous pegmatites. It can be found in rocks of all geological ages, from Precambrian to recent formations.

Uses & applications

Used in glass making, as an abrasive, in the production of silicon metal, and as a decorative stone in landscaping or low-cost jewelry.

Geological facts

The milky appearance is caused by tiny inclusions of gas or liquid trapped during the crystal's growth. It is the most common variety of crystalline quartz found on Earth's crust.

Field identification & locations

Identify in the field by its hardness (scratches glass), lack of cleavage, and white 'milky' opacity. It is ubiquitous globally, especially in mountain ranges and riverbeds.