mineral

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: White to translucent; Luster: Vitreous (glassy) to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

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

Identified February 6, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: White to translucent; Luster: Vitreous (glassy) to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed through the cooling of magma or by hydrothermal activity where silica-rich fluids crystallize in rock cavities and veins. It is found in igneous, metamorphic, and sedimentary environments globally.

Uses & applications

Extensively used in the glass and ceramics industry, electronics (as oscillators), abrasives, construction (as aggregate), and as a gemstone or specimen for collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz gets its cloudy appearance from tiny fluid inclusions of gas or liquid trapped during crystal growth.

Field identification & locations

Identify by its ability to scratch glass (hardness 7) and its lack of cleavage. It is commonly found in gravel pits, mountain ranges, and near volcanic sites. Collectors look for well-defined crystal points.