mineral

Amethyst (purple quartz), likely a rough crystal fragment

Quartz, SiO₂; purple color from trace iron and irradiation

AI-generated identification · may be incorrect

Hardness 7 Mohs; translucent lavender-purple color, vitreous luster, conchoidal fracture, and no cleavage. The small specimen appears irregular and may have been broken or partly polished; crystal form is not clearly visible.

Identified August 18, 2026More mineral →

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Physical properties

Formation & geological history

Amethyst forms when iron-bearing quartz grows in gas bubbles or fractures within volcanic rocks, commonly basalt and rhyolite. Most specimens formed in geologically young-to-ancient hydrothermal cavities; exact age and locality cannot be determined from the image.

Uses & applications

Used as an ornamental gemstone, jewelry, carvings, and mineral specimens. Common small rough fragments generally have modest commercial value.

Geological facts

Color intensity varies with iron content and irradiation, and heating can turn amethyst yellow or orange, producing citrine. It is the February birthstone.

Field identification & locations

Identify by its purple hue, glassy luster, hardness, and quartz-like fracture; it should scratch ordinary glass but not be scratched by a steel knife. Common sources include Brazil, Uruguay, Zambia, and Madagascar.