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
Amethyst Incident largely based on the events of the Yangtze incident. Richard Todd starred as Kerans in the 1957 film "Yangtse Incident: The Story of HMS Amethyst" (in the US most commonly released as "Battle Hell", but also as "Escape of the Amethyst" and "Their Greatest Glory"). For the film, "Amethyst" was brought out of storage to play herself. As her engines were no longer operational, her sister ship, , was used for shots of the ship moving. Amethyst Incident The "Amethyst" Incident, also known as the Yangtze Incident, was a historic event which involved the Royal Navy ship HMS "Amethyst" on