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
Yangtse Incident: The Story of H.M.S. Amethyst le Yangtse" (French) and "Vuur op de Yangtse" (Flemish/Dutch), both meaning ""Fire on the Yangtse"". The film was entered into the 1957 Cannes Film Festival. On 19 April 1949, the Royal Navy sloop HMS "Amethyst" sails up the Yangtze River on her way to Nanking, the Chinese capital, to deliver supplies to the British Embassy. Suddenly, without warning, People's Liberation Army (PLA) shore batteries open fire and after a heavy engagement, "Amethyst" lies grounded in the mud and badly damaged. attempts to tow "Amethyst" off the mud bank, but is herself hit several times and has to depart. A further