Amethyst

Hardness of 7 on the Mohs scale, purple to violet color, vitreous luster, trigonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65.

Forms in hydrothermal veins and gas cavities (vugs and geodes) in volcanic rocks, where silica-rich solutions cool and crystallize over millions of years.

Widely used as a gemstone in jewelry, for ornamental carvings, and as a popular mineral specimen for collectors.

The purple color is caused by irradiation, iron impurities, and the presence of trace elements. Historically, amethyst was considered a precious gemstone of equal value to diamond and ruby until large deposits were discovered in Brazil.

Easily identified by its distinct purple coloration and hardness of 7, which scratches glass. Found worldwide, with major deposits in Brazil, Uruguay, Zambia, and the United States.