Amethyst element impurities), and the presence of trace elements, which result in complex crystal lattice substitutions. The hardness of the mineral is the same as quartz, thus it is suitable for use in jewelry. Amethyst occurs in primary hues from a light pinkish violet to a deep purple. Amethyst may exhibit one or both secondary hues, red and blue. The best varieties of amethyst can be found in Siberia, Sri Lanka, Brazil and the far East. The ideal grade is called "Deep Siberian" and has a primary purple hue of around 75–80%, with 15–20% blue and (depending on the light source)
HMS Amethyst (1799) Frigate, at the Action of 6 April 1809. "Niémen" had 47 killed and 73 wounded; "Amethyst" had eight killed and 37 wounded. In 1847 the Admiralty authorized the issue of the Naval General Service Medal with clasp "Amethyst 5 April 1809". Later in the year, Seymour participated in the Walcheren Expedition, providing naval support to the transports. On 11 August she was part of a squadron under Captain William Stewart that forced the passage between shore batteries at Flushing and Cadsand. "Amethyst" had one man killed and one man wounded in the operation. Seymour left the ship in 1809; his