mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Opaque white to translucent
Luster: Vitreous to greasy

Identified April 22, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. The milky appearance is caused by tiny bubbles of gas or liquid trapped during crystal growth. It can be found in rocks from almost any geological age.

Uses & applications

Used as a gemstone in jewelry (cabochons), in glass making, as an abrasive, and extensively in construction as road metal or landscaping gravel. High-purity quartz is used in electronics for its piezoelectric properties.

Geological facts

Milky Quartz is the most common variety of crystalline quartz. It is often found as the 'vein mineral' that carries gold in gold-bearing regions. The white color is specifically due to microscopic fluid inclusions present since the time of formation.

Field identification & locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and white 'cloudy' appearance. It is found globally, particularly in mountainous regions, riverbeds, and as part of granite outcrops.