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 go from Shanghai to Kiangyin, 40 miles down river from the "Amethyst". "Consort" reached the "Amethyst" at about three in the afternoon and was immediately fired upon. She found the fire too heavy to approach "Amethyst" and therefore passed her at speed down river. She turned two miles below and again closed "Amethyst" to take her in tow. But again she came under such heavy fire that she was obliged to abandon the attempt, although she answered the shore batteries with her full armament (including 4.5-inch (114 mm) guns) and soon signaled that she had silenced most of the opposition.