Mineral

Milky Quartz (among River Rock)

Quartz (Silicon Dioxide, SiO2)

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

Hardness: 7 on Mohs scale
Color: Milky white to translucent
Luster: Vitreous (glassy) to greasy

Identified March 8, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal solutions in veins or as a major constituent of igneous rocks like granite. The rounded shape indicates significant water erosion/tumble in a river or glacial environment over thousands to millions of years.

Uses & applications

Used in landscaping (river rock), production of glass, electronics (piezoelectric properties), abrasives, and as building material or road aggregate.

Geological facts

Milky quartz gets its white color from tiny microscopic inclusions of gas or liquid trapped during the crystal's growth. It is the most common variety of crystalline quartz found on Earth's surface.

Field identification & locations

Identify in the field by its ability to scratch glass, its lack of cleavage (it breaks into irregular, sharp shards), and its resistance to weathering compared to surrounding softer minerals. Commonly found in riverbeds, glacial tills, and mountainous regions worldwide.

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