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
Amethyst Incident not see "Amethyst" in the dark. When the battery opened fire, the fire was directed at the "Kiang Lin Liberation" which was sunk by the gun fire, with heavy civilian casualties. At 0500 hours on 31 July, "Amethyst" approached the PLA forts at Par Shan (Baoshan) and Woosung (Wusong) which had their searchlights sweeping the river. At 0525 a planned meeting with the destroyer took place, at which point "Amethyst" sent the signal "Have rejoined the fleet south of Woosung. No damage. No casualties. God save the King". "Concord" had been ordered to prepare to provide gun support to "Amethyst"