Opal Types

The Australian Opal and Diamond Collection mines its precious gem stones from the world renowned Opal fields in Australia. 

Australian Opal is found at the following mine locations: 
Coober Pedy | Andamooka | Mintabie | Lambina | Lightning Ridge | Opalton

Opal is a form of silica, chemically similar to quartz, but containing water within the actual structure. Precious Opal usually contains 6-10% water and consists of small deposits of silica spheres arranged in a regular pattern.

There are six different types of opal to consider: 
Black | Boulder | Crystal | Milky | Doublet | Triplet


Triplet Opal

A three layered gem adhered together comprising first of clear capping usually quartz. Second precious Opal and third a common Opal backing. This process allows for a colourful stone at a fraction of the cost.

Doublet Opal

A two layered gem adhered together, comprising first of the precious Opal. Second common Opal backing. This process is similar to a venire.


Milky Opal

Milky Opal is a solid form of Common Opal. Sandstone and potch (impurities) make up the base of this stone, thus giving it a cloudy milky appearance. Commonly mined in Coober Pedy, South Australia.

Boulder Opal

Boulder Opal is a Solid form of Opal. It comprises of natural Iron stone. This Iron is the host structure and often has an undulating surface. Commonly mined in Quilpie, Queensland.

Crystal Opal

Crystal Opal is a Solid form of Opal. It is a full silicon base as host structure. It has little impurity hense allowing light light pass through, giving a translucent appearance. Commonly mined in Andamooka, South Australia.

Black Opal

Black Opal is a Solid form of Opal. It has a manganese oxide base as host structure. The level of manganese is indicated by a index level from N1 being the darkest to N7 the lightest. Black Opal is considered to be the most rare and is mined in Lightning Ridge, New South Wales.