mineral

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

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

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

Identified April 5, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. It can be found in a wide variety of geological environments and ages, from ancient Precambrian shields to modern volcanic areas.

Uses & applications

Used in electronics (oscillators), glassmaking, abrasives, jewelry, and as a popular collector specimen for its crystal forms.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its 'milky' appearance is caused by tiny fluid inclusions of gas or liquid trapped during crystal growth.

Field identification & locations

Identify in the field by its hardness (it scratches glass), lack of cleavage, and translucent white appearance. Commonly found as river stones, in mountain ranges, or as veins in igneous rocks.