mineral

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

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

Identified May 1, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Opaque white to beige; 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 through hydrothermal precipitation in veins. Found in igneous, metamorphic, and sedimentary environments worldwide.

Uses & applications

Used in manufacturing of glass, ceramics, and abrasives. High-purity quartz is used in electronics and clocks. Common specimens are used for landscaping and amateur collecting.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is piezo-electric, meaning it can generate an electric charge when mechanical stress is applied.

Field identification & locations

Identify by its hardness (it can scratch glass and steel) and lack of cleavage. Often found in riverbeds, mountains, and as a primary component of sand.