Quartz

Physical Properties

Hardness: 7 on Mohs scale. Color: can be clear, milky white, gray, or lightly tinted by impurities. Luster: Vitreous (glassy) to greasy. Crystal structure: Hexagonal (though often massive like this piece). Cleavage: None, exhibits conchoidal fracture. Specific gravity: 2.65.

Formation & Geological History

Forms in igneous, metamorphic, and sedimentary rocks. Common in pegmatites, hydrothermal veins, and as a primary constituent of granite and sandstone. The geological age can range broadly depending on the formation conditions.

Uses & Applications

Used widely in glassmaking, abrasives, foundry sand, hydraulic fracturing, electronics (piezoelectric properties), and as a gemstone or ornamental stone.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Its piezoelectric properties make it essential in watches, radios, and microprocessors.

Field Identification & Locations

Identify by its hardness (scratches glass), lack of cleavage, conchoidal fracture, and glassy luster. Found worldwide in almost all geological environments.

Identified on: 4/26/2026

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