Types of Opal
Black Opal or Opal with a dark grey body shows the most brilliant play of colours imaginable. Crystal opal, which comes immediately after Black Opal in the hit list, should be more transparent with a deep play of colours. White or milky Opals show more diffuse colours and are the least expensive Opals.
Solid Opals. A solid opal, as the name implies, is a single piece of opal. Solids may be cut into a variety of shapes ranging from circular hemispheres and ovals to free-flowing shapes that follow the natural lines of the stone.
Doublet Opals. Doublets are created by taking a thin sliver of natural crystal opal, then attaching it with jewellers cement to a natural black opal backing. (The backing is called black potch and lacks the play of colour charateristic of opal.)
Triplet Opals. A triplet is also a composite piece. To create a triplet, the jeweler takes a sliver of natural crystal opal, then attaches it with jewellers cement to a backing of black potch. A cap of clear quartz is then placed on top of the opal sliver, creating, if you will, a sandwich effect.
Most solid opals and doublets are cut and polished with a convex dome or curved top. This encourages light into the stone so that the opal’s irridescent properties are shown at their best. For triplets, the dome is created by a crystal cap that covers the flat slice of opal.
