Amethyst
Amethyst is found at many localities in Southern Africa. It is a mauve to purple variety of quartz. Its colour is the result of Fe3 ions being found in its atomic lattice. In many cases the mineral has the distinctive habit of forming prisms that except for the terminations get coated with a multitude of tiny drusy crystals. This has given rise to it sometimes being referred to as ‘cactus crystals’. It is also sometimes referred to as ‘spirit quartz’ perhaps because some of the crystals are the colour of methylated spirits. Amethyst is found in South Africa, Namibia, Zimbabwe and Swaziland.
Chemical Formular : SiO2
Refractive Index : 1,54 – 1,55
Hardness : 7 on the Mohs Scale
Crystal System : Hexagonal