Quartz Distinctive Features
Quartz is one of the most common semi precious stones found throughout Australia. It is usually associated with sedimentary igneous and metamorphic rocks. Quartz Crystals generally occur as hexagonal prisms with termmations shaped in the form of a pyramid. Quartz has a rating of 7 on the Mohs scale.
The silicate group cover many varieties of stone Chalcedony, Agate, Chameleon, Chrysoprase and Rose Quartz. White or Milky Quartz and Flint are also amongst them however,
the discussion here will centre on the four key varieties listed.
The pure form of Quartz is clear colourless, other colours and varieties are caused by minute traces of other material such as lithium, manganese, ferric iron and titanium etc. Citrine for instance is coloured by yellow traces of ferric hydroxide. Cairngorm is a smoky yellow or darker brown colours caused by traces of aluminium.