mineral

Amethyst cluster

Quartz, SiO₂; purple variety colored mainly by trace iron and irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; translucent purple crystals with vitreous luster and hexagonal crystal system. Quartz has no cleavage and typically breaks with conchoidal fracture.

Identified September 28, 2026More mineral →

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Physical properties

Mohs hardness 7; translucent purple crystals with vitreous luster and hexagonal crystal system. Quartz has no cleavage and typically breaks with conchoidal fracture.

Formation & geological history

Forms as quartz crystals in silica-rich hydrothermal fluids within cavities and veins; specimens range from recent to hundreds of millions of years old, depending on deposit.

Uses & applications

Used in jewelry, carvings, and mineral collections; clusters are commonly displayed as decorative specimens.

Geological facts

Amethyst’s purple color is associated with iron impurities and natural radiation exposure; heating can alter its color toward yellow or orange.

Field identification & locations

Identify by purple, glassy quartz crystals and hardness near 7; common sources include Brazil, Uruguay, and Zambia. Estimated value: about $10–$100 for a small, ordinary cluster, more for large or vivid specimens.