Amethyst and it can not be differentiated with absolute certainty without advanced gemmological testing (which is often cost-prohibitive). There is one test based on "Brazil law twinning" (a form of quartz twinning where right and left hand quartz structures are combined in a single crystal) which can be used to identify synthetic amethyst rather easily. It is possible to synthesize twinned amethyst, but this type is not available in large quantities in the market. Single-crystal quartz is very desirable in the industry, particularly for keeping the regular vibrations necessary for quartz movements in watches and clocks, which is where a lot
Yangtse Incident: The Story of H.M.S. Amethyst Yangtse Incident: The Story of H.M.S. Amethyst Yangtse Incident: The Story of H.M.S. Amethyst (1957) is a British war film that tells the story of the British sloop caught up in the Chinese Civil War and involved in the 1949 Yangtze Incident. It was based upon the book written by Lawrence Earl. The film was known in the US by the alternative titles Battle Hell, "Escape of the Amethyst", "Their Greatest Glory" and "Yangtze Incident". Non-English language titles include the direct German translation of "Yangtse-Zwischenfall", and "Commando sur le Yang-Tse" in France. In Belgium it was known as "Feu sur