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 largely based on the events of the Yangtze incident. Richard Todd starred as Kerans in the 1957 film "Yangtse Incident: The Story of HMS Amethyst" (in the US most commonly released as "Battle Hell", but also as "Escape of the Amethyst" and "Their Greatest Glory"). For the film, "Amethyst" was brought out of storage to play herself. As her engines were no longer operational, her sister ship, , was used for shots of the ship moving. Amethyst Incident The "Amethyst" Incident, also known as the Yangtze Incident, was a historic event which involved the Royal Navy ship HMS "Amethyst" on