mineral
Quartz crystal cluster
Quartz (silicon dioxide, SiO₂), likely pale amethyst or iron-stained quartz
AI-generated identification · may be incorrectHardness 7 Mohs; colorless to smoky-lavender, vitreous luster, transparent to translucent, hexagonal crystal structure, and no true cleavage but conchoidal fracture. The pointed prismatic crystals and glassy faces are diagnostic.
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Physical properties
Hardness 7 Mohs; colorless to smoky-lavender, vitreous luster, transparent to translucent, hexagonal crystal structure, and no true cleavage but conchoidal fracture. The pointed prismatic crystals and glassy faces are diagnostic.
Formation & geological history
Quartz crystallizes from silica-rich hydrothermal fluids or late-stage cavities in igneous and metamorphic rocks, commonly over millions of years. The purple tint, if genuine, results from trace iron plus natural irradiation.
Uses & applications
Used for mineral collecting, ornamentation, and occasionally jewelry; quartz is also important industrially in glass, electronics, abrasives, and optical instruments.
Geological facts
Quartz is piezoelectric: pressure generates an electrical charge, enabling watches and sensors. Amethyst is purple quartz, while smoky coloration is produced by radiation-related defects.
Field identification & locations
Look for six-sided prisms ending in pyramidal points, hardness sufficient to scratch glass, and conchoidal breakage. Common sources include Brazil, Uruguay, Madagascar, the United States, and alpine-type veins; this specimen may also be coated or artificially colored.
