One of our most popular gems, Amethyst, is the birthstone for February and the 6th Anniversary gem. Until the 18th century, amethyst was one of the most valuable gemstones along with diamond, sapphire, ruby and emerald, a cardinal gem. Value decreased when very large deposits were found coming out of Brazil. Today most amethyst is still coming out of Brazil or Uruguay but amethyst is found throughout the world. Carat weight is not the biggest concern when buying amethyst but color declares the value. Depth of color and color display is a biggest factor in determining value. The Greeks believed amethyst gems could prevent intoxication.