mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7.0 on Mohs scale; Color: Cloudy white or milky; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7
Color: Cloudy white or milky
Luster: Vitreous to greasy

Identified May 25, 2026More mineral →

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Physical properties

Hardness: 7.0 on Mohs scale; Color: Cloudy white or milky; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Formed from silica-rich hydrothermal fluids cooling in veins or as a late-stage mineral in igneous rocks like granite. The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in glassmaking, ceramics, electronics (as a source of silicon), construction aggregate, and as a decorative stone in landscaping or lapidary work.

Geological facts

Milky quartz is the most common variety of crystalline quartz. Its cloudiness is due to microscopic fluid inclusions that occurred during its formation millions of years ago.

Field identification & locations

Identify by its white color, ability to scratch glass (hardness), and lack of cleavage (breaks like glass). Commonly found in riverbeds, mountain ranges, and garden landscaping.