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 brig "Rising Sun". On 10 March 1808 "Amethyst" captured the Spanish brig "Vigilantie". Eleven days later "Amethyst" recaptured the Portuguese schooner "Inseperavil Unio". On 3 May "Amethyst" and captured the French sloop "Actif". Sixteen days later, "Amethyst", "Conflict", and were in company when they captured the French schooner "Annais". The next month, on 10 June, "Amethyst" and "Conflict" captured the Spanish schooner "Carmelita". Fourteen days later, "Amethyst" captured the American brig "Sally Tracey". Then "Amethyst" was again in company with "Growler" when they captured "St. Etienne", "Maria Julia", and six chasse marees on 9 July. Lastly, on 17 September