mineral

Amethyst (rough specimen)

Quartz, SiO₂; purple color commonly caused by iron-related defects and natural irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; translucent purple with a vitreous luster and irregular fracture. The photo does not show diagnostic crystal faces, so identification is provisional.

Identified October 2, 2026More mineral →

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Physical properties

Mohs hardness 7; translucent purple with a vitreous luster and irregular fracture. The photo does not show diagnostic crystal faces, so identification is provisional.

Formation & geological history

Forms when silica-rich fluids deposit quartz in cavities, commonly in volcanic rocks; deposits range from geologically recent to hundreds of millions of years old.

Uses & applications

Used for jewelry, carvings, and mineral collecting; lower-grade material may be used decoratively.

Geological facts

Amethyst is the purple variety of quartz and can fade with prolonged exposure to strong sunlight or heat.

Field identification & locations

Look for purple quartz that scratches glass and lacks obvious cleavage; common sources include Brazil, Uruguay, Zambia, and other volcanic or hydrothermal regions. This small, rough piece is roughly $1–$10 USD.