Amethyst element impurities), and the presence of trace elements, which result in complex crystal lattice substitutions. The hardness of the mineral is the same as quartz, thus it is suitable for use in jewelry. Amethyst occurs in primary hues from a light pinkish violet to a deep purple. Amethyst may exhibit one or both secondary hues, red and blue. The best varieties of amethyst can be found in Siberia, Sri Lanka, Brazil and the far East. The ideal grade is called "Deep Siberian" and has a primary purple hue of around 75–80%, with 15–20% blue and (depending on the light source)
Yangtse Incident: The Story of H.M.S. Amethyst rescue attempt by two other ships also comes under heavy fire and has to be aborted. Fifty-four of "Amethyst"s crew are dead, dying or seriously wounded, while others deteriorate from the tropical heat and the lack of essential medicines, including the ship's captain, who dies of his wounds. An attempt to evacuate the wounded is only partially successful - the officers of the "Amethyst" become aware that two petty officers have been captured by the PLA and are being held at a nearby military hospital. Lieutenant Commander John Kerans (Richard Todd), a naval attaché in nearby Nanking, is ordered to