mineral

Amethyst-bearing quartz geode or vein specimen

Quartz, SiO₂; purple coloration from trace iron and irradiation

AI-generated identification · may be incorrect

Hardness 7 Mohs; vitreous luster; translucent white to lavender-purple color; hexagonal crystal structure and indistinct cleavage. The specimen appears as massive milky quartz with scattered amethyst crystals, likely on a feldspar- or carbonate-rich matrix.

Identified August 17, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids or volcanic cavities deposit quartz, with later iron-related coloration producing amethyst. Amethyst commonly formed from the late Paleozoic to Cenozoic, depending on locality.

Uses & applications

Used for gemstones, ornaments, mineral collections, and crystal displays; massive quartz has industrial uses in glass and engineered materials.

Geological facts

Amethyst is the purple variety of quartz and ranks 7 on the Mohs scale, making it durable but still vulnerable to scratching and heat-induced color fading.

Field identification & locations

Identify it by purple quartz, glassy luster, and hardness sufficient to scratch ordinary glass; it commonly occurs in Brazil, Uruguay, Zambia, Mexico, and the United States. A definitive identification may require locality information or testing.