mineral

Amethyst (rough crystal specimen)

Quartz, SiO₂; purple coloration commonly caused by trace iron and natural irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; purple to violet, vitreous luster, trigonal crystal structure, no true cleavage, and conchoidal fracture. The specimen is rough and appears to include a pale quartz matrix.

Identified October 7, 2026More mineral →

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Physical properties

Mohs hardness 7; purple to violet, vitreous luster, trigonal crystal structure, no true cleavage, and conchoidal fracture. The specimen is rough and appears to include a pale quartz matrix.

Formation & geological history

Amethyst forms when silica-rich fluids deposit quartz in cavities, commonly in volcanic rocks; trace iron and irradiation produce its color. Such deposits formed across many geological ages, so the specimen’s age cannot be determined from the image.

Uses & applications

Used for jewelry, carvings, decorative objects, and mineral collecting; rough crystals are also sold as display specimens.

Geological facts

Amethyst is the purple variety of quartz. Heating can alter its color, sometimes producing yellow-orange citrine-like material.

Field identification & locations

Identify it by its purple color, glassy luster, hardness, and quartz crystal habit; notable sources include Brazil, Uruguay, Zambia, and parts of the United States. The label appears to describe this as a rough amethyst crystal specimen.