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 brig "Rising Sun". On 10 March 1808 "Amethyst" captured the Spanish brig "Vigilantie". Eleven days later "Amethyst" recaptured the Portuguese schooner "Inseperavil Unio". On 3 May "Amethyst" and captured the French sloop "Actif". Sixteen days later, "Amethyst", "Conflict", and were in company when they captured the French schooner "Annais". The next month, on 10 June, "Amethyst" and "Conflict" captured the Spanish schooner "Carmelita". Fourteen days later, "Amethyst" captured the American brig "Sally Tracey". Then "Amethyst" was again in company with "Growler" when they captured "St. Etienne", "Maria Julia", and six chasse marees on 9 July. Lastly, on 17 September