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) company with , captured "Agnela". On 30 July "Amethyst" captured the "Ebenezer", and then on 1 August "Amethyst" captured "Juno". In December "Amethyst" participated in the pursuit of a French squadron under Admiral Willaumez. In November 1805 "Amethyst" encountered the brig-sloop off the coast of Madeira. After a series of ambiguous and misinterpreted moves by the other, the two captains mistook each other for enemies and opened fire. Both vessels survived and the two captains proceeded to exchange mutually recriminatory letters. "Amethyst" was among the vessels that shared in the proceeds of the capture, on 25 July 1805, of the