amethyst          
noun uk/ˈæm.ə.θɪst/ us/ˈæm.ə.θɪst/
 [ C or U ]紫水晶 
a transparent purple stone used in jewellery
  She wore a plain necklace of amethysts.
 Bishops and cardinals used to wear amethyst as a symbol of peace.
  [ U ]紫(水晶)色 
a purple colour
  The gown is made from silk crepe fabric in dusty amethyst. 
 - More examples
 - An amethyst is set into the handle of the sword.
 - Amethysts, emeralds, topaz, and sapphires litter workshops like colourful marbles.
 - Her expensive soft woollen coat was a deep shade of amethyst.