Opal in my gemstone collection

Opal in the rough

An Opal is basically Silica who's crystals are formed randomly or amorphous. The areas between the random crystals contain water which usually consists of up to 10% of the gems total weight. 97% of all Opals come from Australia and precious opal ranges from clear through white, red, orange, yellow blue, pink, brown and black. Of these colors the reds against the black are the most rare whereas the whites and greens are the most common.