gemstone

Amethyst cabochon ring

Amethyst, purple quartz (SiO₂)

AI-generated identification · may be incorrect

Hardness 7 Mohs; vitreous luster; purple color from trace iron and irradiation; trigonal quartz crystal structure, with no cleavage and conchoidal fracture. The stone is a polished oval cabochon in a metal setting; the dark appearance may reflect deep color or translucency limitations.

Identified August 19, 2026More gemstone →

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Physical properties

Formation & geological history

Amethyst forms mainly in cavities of volcanic rocks when silica-rich hydrothermal fluids deposit quartz, commonly during basaltic geode formation. Its age varies widely; many commercial specimens formed in Mesozoic to Cenozoic volcanic terrains.

Uses & applications

Used in jewelry, carvings, geode specimens, and ornamental objects. The surrounding ring appears silver-colored, but its exact metal cannot be confirmed visually.

Geological facts

Amethyst is the purple variety of quartz and is February’s birthstone. Heating can turn some amethyst yellow-orange, producing citrine.

Field identification & locations

Identify by purple color, glassy luster, high hardness, and lack of cleavage; it should scratch ordinary glass but not be scratched by a steel knife. Common sources include Brazil, Uruguay, Zambia, and Bolivia; testing requires checking for glass or synthetic imitation.