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) "Amethyst" captured sundry spars. In November 1808 "Amethyst" captured the French frigate "Thétis" at the Action of 10 November 1808. British casualties in the engagement were severe, with 19 killed and 51 wounded, but French losses were several times larger, with 135 dead and 102 wounded. "Amethyst" had been severely damaged in the engagement and repairs took 71 days to complete at Plymouth. Seymour's victory was rewarded: Seymour himself was presented with a commemorative medal, £100 (with £625 to share among the wounded) and the freedoms of Cork and Limerick. The Admiralty awarded him a gold medal; this was one