mineral

Amethyst (likely rough or cleaved fragment)

Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; translucent lavender-purple color, vitreous luster, conchoidal fracture, and no true cleavage. The specimen appears massive rather than showing distinct quartz crystals; specific gravity is about 2.65.

Identified August 11, 2026More mineral →

Explore Amethyst (likely rough or cleaved fragment) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids fill cavities in volcanic rocks, commonly with agate and quartz; many amethyst geodes formed in basalt during the Cenozoic. Purple color develops from iron-related color centers exposed to natural radiation.

Uses & applications

Used for inexpensive jewelry, carvings, polished stones, geodes, and mineral collecting. It has substantial decorative value but is not generally rare.

Geological facts

Amethyst is the February birthstone and is the purple variety of quartz. Heating can turn some material yellow-orange, producing citrine or ametrine-like colors.

Field identification & locations

Identify it by its purple quartz appearance, glassy luster, hardness, and resistance to scratching by steel; glass can resemble it but is generally softer and lacks quartz texture. Common sources include Brazil, Uruguay, Zambia, and Mexico.