mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White, milky, opaque; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White, milky, opaque
Luster: Vitreous to greasy

Identified May 20, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White, milky, opaque; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Formed through the crystallization of silica from hydrothermal veins, pegmatites, and igneous melt. The milky color is caused by microscopic fluid bubbles or gas trapped during the crystal growth process.

Uses & applications

Used in glassmaking, silicon production for electronics, as an abrasive, and widely used in landscaping and decorative gravel. It is also a popular specimen for beginner mineral collectors.

Geological facts

Milky quartz is the most common variety of crystalline quartz on Earth. Its white color is often due to 'frozen' bubbles of liquid or gas dating back billions of years to when the stone was cooling.

Field identification & locations

Identify by its ability to scratch glass and lack of cleavage. It is commonly found in gravel pits, riverbeds, and as veins in mountain ranges worldwide. Collectors should look for clean white surfaces and lack of iron staining.