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) "Jonge Jacob". Captain Michael Seymour replaced Spranger. On 15 May 1807, "Amethyst" captured the privateer "Josephine" some 20 leagues from Scilly. "Josephine" was armed with four 2-pounders guns and small arms. She had a crew of 45 men, but had put ten on board "Jane", which had been sailing from Lisbon. "Josephine" had sailed from the Île de Batz and "Jane" was her only capture. When "Amethyst" captured "Josephine", "Amethyst" was in company with and . Then on 9 September "Amethyst" captured the Danish ship "Twende Venner". Later, on 18 October, "Amethyst" recaptured the ship "Susannah". "Amethyst" also recaptured the