Amethyst element impurities), and the presence of trace elements, which result in complex crystal lattice substitutions. The hardness of the mineral is the same as quartz, thus it is suitable for use in jewelry. Amethyst occurs in primary hues from a light pinkish violet to a deep purple. Amethyst may exhibit one or both secondary hues, red and blue. The best varieties of amethyst can be found in Siberia, Sri Lanka, Brazil and the far East. The ideal grade is called "Deep Siberian" and has a primary purple hue of around 75–80%, with 15–20% blue and (depending on the light source)
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