Opal

Opal (noun): A non crystalline form of the mineral silica which, despite its amorphous structure, displays an amazing degree of internal organization.

Australian Opals

Black Opal

Crystal Opal

White Opal

Boulder Opal

Matrix Opal

Mining Areas

Coober Pedy

Lightning Ridge

Mintabie

Andamooka

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 Australian Opals

Interestingly, all Australian opal is of sedimentary formation and occurred when the inland sea that covered a large area of mainland Australia receded and then began to dry, over 150 million years ago.

Silica rich waters found their way into faults and cracks and traveled deep within the earth, where they slowly set about evolving into the most beautiful gemstone in the world, opal.

Most of the world's opal is mined in Australia at Coober Pedy, Lightning Ridge, Andamooka, Mintabie and Lambina, with some smaller fields scattered across South Australia, New South Wales and Queensland.

Geological Definition: [Alternative term:Opaline silica]

Includes all hydrates of silica, SiO2 nH2O, including synthetic, natural precious and common opal but not imitation material.

TIP: Opal that does not exhibit a play of colors is referred to as potch.

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