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) HMS Amethyst (1799) HMS "Amethyst" was a Royal Navy 36-gun "Penelope"-class fifth-rate frigate, launched in 1799 at Deptford. "Amethyst" served in the French Revolutionary Wars and the Napoleonic Wars, capturing several prizes. She also participated in two boat actions and two ship actions that won her crew clasps to the Naval General Service Medal. She was broken up in 1811 after suffering severe damage in a storm. "Amethyst" was commissioned in May 1799 under the command of Captain John Cooke. She then operated on the Dutch coast later that year. During the Anglo-Russian invasion of Holland, "Amethyst" conveyed the Duke