Stone Beads - 18mm - Square - Dog Tooth Amethyst (strand)

Amethyst is the purple variation of Quartz, and Citrine is the amber-yellow colouring of it - the colour is determined by the minerals present in the stone when it it being formed. For instance, the iron and aluminum give the purple colour to Amethyst. (There is a fascinating article on Amethyst on Wikipedia). Citrine is generally heated Amethyst or Smokey Quartz - heating it changes it's colour. Citrine and Amethyst present in the same stone are known as Ametrine.