mineral

Amethyst (rough crystal)

Quartz, SiO₂; purple coloration typically results from trace iron and natural irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; translucent purple with vitreous luster and irregular fracture. Trigonal crystal structure; no true cleavage. The specimen appears to be a small, rough fragment.

Identified September 26, 2026More mineral →

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Physical properties

Mohs hardness 7; translucent purple with vitreous luster and irregular fracture. Trigonal crystal structure; no true cleavage. The specimen appears to be a small, rough fragment.

Formation & geological history

Forms in silica-rich fluids, commonly lining cavities in volcanic rocks; amethyst deposits range from geologically young to hundreds of millions of years old.

Uses & applications

Used in jewelry, carvings, and mineral collections; common small rough pieces have modest value.

Geological facts

Amethyst is the purple variety of quartz, and its color can fade with prolonged heat or sunlight.

Field identification & locations

Look for purple quartz with glassy luster and hardness sufficient to scratch ordinary glass. Major sources include Brazil, Uruguay, Zambia, and Madagascar.