mineral

Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Hardness: 7.0 on Mohs scale; Color: Colorless to white; Luster: Vitreous (glassy); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7
Color: Colorless to white
Luster: Vitreous (glassy)

Identified May 19, 2026More mineral →

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Physical properties

Hardness: 7.0 on Mohs scale; Color: Colorless to white; Luster: Vitreous (glassy); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Forms in a wide variety of environments including igneous (granite), metamorphic (quartzite), and sedimentary rocks. It crystallizes from silica-rich hydrothermal fluids or cooling magma.

Uses & applications

Used in electronics (oscillators), optics, abrasives, glassmaking, and frequently as a gemstone or for decorative collecting.

Geological facts

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

Field identification & locations

Identify by its ability to scratch glass and lack of cleavage. Often found near granite outcrops, in riverbeds, or as veins within larger rock bodies. Very common worldwide.