Amethyst is not primarily defined by carat weight; this is different to most gemstones where the carat weight exponentially increases the value of the stone. The biggest factor in the value of amethyst is the color displayed. The highest grade amethyst (called "Deep Russian") is exceptionally rare and therefore, when one is found, its value is dependent on the demand of collectors. It is, however, still orders of magnitude lower than the highest grade sapphires or rubies (padparadscha sapphire or "pigeon's blood" ruby). Amethyst Amethyst is a violet variety of quartz. The name comes from the Koine Greek ἀμέθυστος "amethystos" from
HMS Amethyst (1799) Frigate, at the Action of 6 April 1809. "Niémen" had 47 killed and 73 wounded; "Amethyst" had eight killed and 37 wounded. In 1847 the Admiralty authorized the issue of the Naval General Service Medal with clasp "Amethyst 5 April 1809". Later in the year, Seymour participated in the Walcheren Expedition, providing naval support to the transports. On 11 August she was part of a squadron under Captain William Stewart that forced the passage between shore batteries at Flushing and Cadsand. "Amethyst" had one man killed and one man wounded in the operation. Seymour left the ship in 1809; his