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
HMS Amethyst (1873) HMS Amethyst (1873) HMS "Amethyst" was the lead ship of the s built for the Royal Navy in the early 1870s. She participated in the Third Anglo-Ashanti War in 1873 before serving as the senior officer's ship for the South American side of the South Atlantic. The ship was transferred to the Pacific Station in 1875 and fought in the Battle of Pacocha against the rebellious Peruvian ironclad warship "Huáscar" two years later. This made her the only British wooden sailing ship ever to fight an armoured opponent. After a lengthy refit, "Amethyst" again served as the senior officer's ship