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 and unwounded men who had been sent ashore. He assumed command of the ship that day. During the next few days "Amethyst" moved several times, but each time she got under way the batteries opened fire at her and the ship was forced to anchor, finally finishing up off Fu Te Wei. On 21 April a signal was received: ""HM ships" London "and" Black Swan "are moving up river to escort the" Amethyst "down stream. Be ready to move."" The cruiser and the frigate (ex-sloop and "Amethyst"s sister ship) were heavily shelled as they attempted to help "Amethyst" and retreated