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
SS Empire Amethyst to lose her pursuer at 00:24 on 13 April by making a sharp turn. At 01:27 hrs, Kölle ordered his engines stopped to try to ascertain where "Empire Amethyst" was. Kölle decided to head in the direction that "Empire Amethyst" was generally heading and by 04:30 had found her again. At 05:52, Kölle aimed the first of two torpedoes at "Empire Amethyst", which hit under the bridge. The second exploded forward of the engine room and she exploded in a mass of flames that were visible from away. "Empire Amethyst" sank with the loss of all 47 crew at .