mineral

Quartz (Citrine or Iron-Stained)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: Pale yellow to brownish-orange. Luster: Vitreous (glassy). Crystal Structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Pale yellow to brownish-orange
Luster: Vitreous (glassy)

Identified June 22, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale. Color: Pale yellow to brownish-orange. Luster: Vitreous (glassy). Crystal Structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Formation & geological history

Formed in igneous (pegmatites) or metamorphic environments, or as a secondary mineral in hydrothermal veins. Yellow coloration is caused by iron impurities or heat treatment of amethyst.

Uses & applications

Used extensively in jewelry, as gemstone specimens for collectors, and in electronics for its piezoelectric properties.

Geological facts

Crystalline quartz is one of the most abundant minerals in the Earth's crust. Natural citrine is rare; many commercial specimens are heat-treated amethyst.

Field identification & locations

Identify by its hardness (scratches glass), lack of cleavage, and glassy appearance. Found globally, especially in Brazil, Madagascar, and the USA.

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Mineral/Rock

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Metamorphic Rock

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mineral