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 (1799) "Jonge Jacob". Captain Michael Seymour replaced Spranger. On 15 May 1807, "Amethyst" captured the privateer "Josephine" some 20 leagues from Scilly. "Josephine" was armed with four 2-pounders guns and small arms. She had a crew of 45 men, but had put ten on board "Jane", which had been sailing from Lisbon. "Josephine" had sailed from the Île de Batz and "Jane" was her only capture. When "Amethyst" captured "Josephine", "Amethyst" was in company with and . Then on 9 September "Amethyst" captured the Danish ship "Twende Venner". Later, on 18 October, "Amethyst" recaptured the ship "Susannah". "Amethyst" also recaptured the