mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: White to opaque
Luster: Vitreous to greasy

Identified May 3, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed from the crystallization of silica-rich hydrothermal fluids in veins or as a major constituent of igneous and metamorphic rocks. The white color is caused by tiny liquid or gas inclusions trapped during crystal growth.

Uses & applications

Used as a gemstone (cabochons), in glassmaking, as a source of silicon for electronics, in construction as aggregate, and in landscaping.

Geological facts

Milky quartz is the most common variety of crystalline quartz. It is often found in massive form rather than distinct crystals, making it a staple of many geological environments worldwide.

Field identification & locations

Identify by its hardness (scratches glass), lack of cleavage, and characteristic waxy-to-vitreous white appearance. Found globally in rivers, beaches, and mountain outcrops.