mineral

Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Colorless to white (milky) with brownish dirt/staining; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Colorless to white (milky) with brownish dirt/staining
Luster: Vitreous to greasy

Identified April 20, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes, crystallization from cooling magma, or precipitation from silica-rich fluids. It can be found in almost all geological environments and ranges from millions to billions of years old.

Uses & applications

Used in glassmaking, abrasives, gemstones, construction materials, and as a component in electronics and watches (piezoelectric properties). Large or unique specimens are valued by collectors.

Geological facts

Quartz is one of the most abundant minerals in the Earth's crust. It is a major component of granite and sandstone. Milky quartz, like this specimen, gets its cloudy appearance from microscopic fluid inclusions trapped during growth.

Field identification & locations

Identify by its hardness (it will scratch glass), lack of cleavage, and conchoidal (glass-like) fracture pattern. Commonly found in veins and as pebbles in riverbeds or beaches worldwide.