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) American ship attempting to dock in a French port. This may have been "Caroline", captured on 14 April. In early June Cooke met up with Captain Sir Edward Pellew's squadron at Quiberon Bay. The squadron engaged in a successful large scale raid on Morbihan, though "Amethyst"s role, if any, is unclear. "Amethyst" was among the vessels of a squadron that shared the proceeds for the recapture on 28 June 1800 of "Lancaster". She was also part of Pellew's squadron, which shared in the proceeds of the capture of "Vigilant", "Menais", "Insolent", "Ann", and the wreck of a vessel that was