mineral

Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Clear to yellowish/tan (Citrine/Smoky variant); Luster: Vitreous/Glassy; Crystal structure: Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Clear to yellowish/tan (Citrine/Smoky variant)
Luster: Vitreous/Glassy

Identified May 5, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Clear to yellowish/tan (Citrine/Smoky variant); Luster: Vitreous/Glassy; Crystal structure: Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Quartz forms in a wide variety of environments, most commonly from the cooling of magma (igneous) or precipitate from hydrothermal veins. It is found in rocks of all geological ages.

Uses & applications

Extensively used in electronics (oscillators), glassmaking, abrasives, and as semi-precious gemstones in jewelry.

Geological facts

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

Field identification & locations

Identify in the field by its hardness (cannot be scratched by a steel knife) and its lack of cleavage. This specimen appears water-worn or tumbled, likely found in a riverbed or coastal area.