Amethyst Sterling Silver RingFebruary's birthstone set in a band that earns a second look. This ring sets a natural amethyst cabochon in solid . 925 sterling silver. Amethyst is the violet variety of quartzMohs hardness 7its color produced by trace iron and natural irradiation during crystal growth, deepening where growth was slowest. The oval cut maximizes the stone's depth of color. Major sources include Brazil, Uruguay, and Zambia. The name derives from the Greek amethystos