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 rescue attempt by two other ships also comes under heavy fire and has to be aborted. Fifty-four of "Amethyst"s crew are dead, dying or seriously wounded, while others deteriorate from the tropical heat and the lack of essential medicines, including the ship's captain, who dies of his wounds. An attempt to evacuate the wounded is only partially successful - the officers of the "Amethyst" become aware that two petty officers have been captured by the PLA and are being held at a nearby military hospital. Lieutenant Commander John Kerans (Richard Todd), a naval attaché in nearby Nanking, is ordered to