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 (1873) HMS Amethyst (1873) HMS "Amethyst" was the lead ship of the s built for the Royal Navy in the early 1870s. She participated in the Third Anglo-Ashanti War in 1873 before serving as the senior officer's ship for the South American side of the South Atlantic. The ship was transferred to the Pacific Station in 1875 and fought in the Battle of Pacocha against the rebellious Peruvian ironclad warship "Huáscar" two years later. This made her the only British wooden sailing ship ever to fight an armoured opponent. After a lengthy refit, "Amethyst" again served as the senior officer's ship