OPAL comes mainly from Australia (95 %), from the dry and hot outback deserts. Dark or Black Opal, White or Light Opal, Milk Opal are some of the different definitions of the colour of this gem, since it varies greatly and has many different shades of colour, except for the Fire Opal, with its red, slightly transparent colour.
Opals which lack these colour changes are simply called Common Opals.
Cultured pearls
Fossils
