This 17.53-carat amethyst displays a rich reddish purple color. - Lydia Dyer, Super Trillion Cut Amethyst gem courtesy of John Dyer & Co. Amethyst has been the most-prized quartz variety for centuries ...

Courtesy Daniel Trinchillo, Fine Minerals International. Amethyst is the purple variety of the quartz mineral species. It’s the gem that’s most commonly associated with the color purple, even though ...