mineral
Amethyst crystal cluster
Quartz (SiO₂), purple variety known as amethyst
AI-generated identification · may be incorrectMohs hardness 7; purple to reddish-purple crystals with vitreous luster and hexagonal crystal structure. Quartz lacks cleavage and has conchoidal fracture; the image shows a small, partly polished or matrix-attached specimen.
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Physical properties
Mohs hardness 7; purple to reddish-purple crystals with vitreous luster and hexagonal crystal structure. Quartz lacks cleavage and has conchoidal fracture; the image shows a small, partly polished or matrix-attached specimen.
Formation & geological history
Amethyst forms as silica-rich fluids deposit quartz in cavities, commonly in volcanic rocks. Its color comes from trace iron and natural irradiation; crystal age depends on the host deposit and cannot be determined from the image.
Uses & applications
Used in jewelry, ornaments, and mineral collecting; lower-grade material is also used for decorative objects.
Geological facts
Amethyst is valued as a birthstone and can fade with prolonged strong sunlight or heat.
Field identification & locations
Look for purple quartz crystals, glassy luster, and hardness sufficient to scratch glass; common sources include Brazil, Uruguay, and Zambia. The small specimen’s exact locality and matrix are not identifiable from the image.
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