Amethyst even if the iron concentration is low. Natural amethyst is dichroic in reddish violet and bluish violet, but when heated, turns yellow-orange, yellow-brown, or dark brownish and may resemble citrine, but loses its dichroism, unlike genuine citrine. When partially heated, amethyst can result in ametrine. Amethyst can fade in tone if overexposed to light sources and can be artificially darkened with adequate irradiation. Amethyst was used as a gemstone by the ancient Egyptians and was largely employed in antiquity for intaglio engraved gems. The largest Ancient Egyptian amethyst mines are located at Wadi el-Hudi and those mines may be the
HMS Amethyst (1799) American ship attempting to dock in a French port. This may have been "Caroline", captured on 14 April. In early June Cooke met up with Captain Sir Edward Pellew's squadron at Quiberon Bay. The squadron engaged in a successful large scale raid on Morbihan, though "Amethyst"s role, if any, is unclear. "Amethyst" was among the vessels of a squadron that shared the proceeds for the recapture on 28 June 1800 of "Lancaster". She was also part of Pellew's squadron, which shared in the proceeds of the capture of "Vigilant", "Menais", "Insolent", "Ann", and the wreck of a vessel that was