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)
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