Amethyst of synthetic quartz is used. Treated amethyst is produced by gamma ray, X-ray or electron beam irradiation of clear quartz (rock crystal) which has been first doped with ferric impurities. On exposure to heat, the irradiation effects can be partially cancelled and amethyst generally becomes yellow or even green, and much of the citrine, cairngorm, or yellow quartz of jewelry is said to be merely "burnt amethyst". The Greek word "amethystos" may be translated as "not drunken", from Greek "a-", "not" + "methustos", "intoxicated". Amethyst was considered to be a strong antidote against drunkenness, which is why wine goblets were
Amethyst Incident state had wrongly invaded Chinese national waters and had fired upon the PLA first. Because the communists (and later the People's Republic of China) did not acknowledge any treaties between the previous Chinese government and the British, they insisted that it was illegal for "Amethyst" to cruise in the Yangtze river. On 30 July 1949 "Amethyst" slipped her chain and headed downriver in the dark, beginning a dash for freedom running the gauntlet of guns on both banks of the river. She followed the passenger ship "Kiang Ling Liberation" in the hope that the observers ashore would be confused and