mineral

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: White to translucent beige, Luster: Vitreous to greasy, Crystal structure: Hexagonal/Trigonal, Cleavage: None (conchoidal fracture)

Identified June 25, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: White to translucent beige, Luster: Vitreous to greasy, Crystal structure: Hexagonal/Trigonal, Cleavage: None (conchoidal fracture)

Formation & geological history

Formed from cooling silica-rich magma or from hydrothermal veins. Often found in pegmatites and metamorphic rocks across many geological ages.

Uses & applications

Used in glassmaking, abrasives, jewelry (semiprecious), and electronics for its piezoelectric properties. Major component in construction aggregate and sand.

Geological facts

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

Field identification & locations

Identified by its ability to scratch glass and lack of cleavage. Commonly found in riverbeds, mountains, and as gravel. Look for the distinct greasy luster on fresh fractures.