Opal Types
Opal Doublets
A piece of solid, natural transparent or translucent-coloured opal is glued to a dark backing (usually black glass), imitating nature's solid stone. The dark base enhances the Opal's colour. Although some doublets can be quite valuable they are also a very cost-effective way of purchasing a beautiful Opal at less expense.
Opal Triplets
A manufactured opal consisting of three layers. A paper-thin slice of solid natural transparent or translucent-coloured opal is glued to a dark backing of black glass, with a dome of clear quartz crystal glued onto the top. The crystal dome is to magnify and protect the opal. A triplet is less expensive than a doublet as less opal is used.
Solid Opals
100% natural opal gemstone, except for cutting and polishing; it has not been altered in any way.
Solid White Opals
This is the most common type of opal. It is found mainly in Coober Pedy, South Australia. Coober Pedy is known as the Opal Capital of the world, it is the world's largest opal field. There are two types of white opal, milky and crystal. Milky opal is opaque, with the colours visible on the surface only, where as crystal opal is transparent, the colors being visible from within the depths of the stone. Coober Pedy is widely known as the the capital for Australian White and Crystal Opal.
Coober Pedy produces the bulk of the world's white Opal. Known as the Opal capital of the world (because of the quantity of precious Opals that are mined there) Coober Pedy is a town in the northern part of South Australia.
It is renowned for below ground residences, mostly in refurbished mines, due to the scorching daytime heat. The harsh summer desert temperatures mean that many residents prefer to live in caves bored into the hillsides ("dugouts"). It remains at a constant temperature, whereas surface living needs air-conditioning, especially during the summer months, when temperatures often exceed 104 degrees fahrenheit.
The Opal from Coober Pedy is mainly light or white Opal and is largely used in the production of doublets and triplets, with the backing layer enhancing the colours of this light Opal.
Boulder Opals
This type of Opal is only found in the Queensland fields. It is opal veinlets found within ironstone boulders. The seam of opal is the face, like an opal veneer with a natural ironstone backing. Boulder Opals have a similar appearance to Black Opals but are less valuable.
Boulder opals comes in a wide array of vibrant colors and patterns and is the strongest type of Opal as it is married to the Ironstone host rock with Winton, Queensland considered the capital of Boulder Opal Country.
Boulder Matrix Opals
This is also found in the Queensland fields, it is a mix of opal veinlets and ironstone. When these are polished, it produces an amazing assortment of stones, some looking like landscapes, others so bright the opal looks like tiny laser beams within the dark brown host rock.
Solid Black Opals
Only found in the Lightning Ridge area in the far north-northwest of New South Wales. It is the world's rarest, most valuable, brilliant and stunning opal of them all. A layer of opal, like a band of colour, sits on a naturally occurring dark backing. It is from the colour of the backing that Black Opal gets its name. This dark background known as potch, ranges in colour from light grey through to midnight black.
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