mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: White to off-white, 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 off-white, opaque
Luster: Vitreous to greasy

Identified May 29, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: White to off-white, 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 magma or hydrothermal veins. The milky appearance is caused by microscopic fluid inclusions of gas or liquid trapped during crystal growth. Can be found in various geological ages globally.

Uses & applications

Used in glassmaking, abrasives, electronics (piezoelectric properties), and as decorative landscaping stone or low-cost collector specimens.

Geological facts

Milky Quartz is the most common variety of crystalline quartz. While it lacks the transparency of rock crystal, it is chemically the same. Large-scale veins of milky quartz are often indicators of potential gold deposits in certain geological settings.

Field identification & locations

Identify by its hardness (it will scratch glass), white opaque color, and lack of cleavage. It is found nearly everywhere in continental crust, especially in mountainous regions or as river pebbles.