It is one of greatest brilliances of nature. This stone can have many colors of the light-arc. The most of opal quality is its performance to reflect particular light wavelengths. The relationship of several light wavelengths provides opal its special visual look, and creates this stone one of the most favorite crystalline all over the world. This is certainly one of the most gorgeous and precious crystalline.
Different kinds of Opal
It exists in a lot of types and varieties. Good quality opal amazingly, is less common than that of unusual emeralds and rubies. There are multiple kinds of Opal available in market:
Black Opal – This opal is the most uncommon and most precious of all types. This opal usually comes in bar. In spite of the name, this type of opal has the all rainbow colors but the outer surface has darker colors for example blue, brown, black or gray.
Boulder Opal – This type of opal is usually exists in the Australia mining fields. This opal is mostly shaped with the ironstone, because the opal bed is usually pretty thin.
General Opal – This type of Opal doesn’t show any space between colors and is regarded as non-gem Opal. This type of opal is reasonably cheap and has very small price as compared to other types of Opals.
Synthetic opal is made in laboratory and is not easy to take part from natural Opal without using laboratory test. The first synthetic opal was made in 1974. A synthetic technique was used called flocculating technique. This technique involves creating colloid silica and clearing surface with sedimentation procedure. This procedure needs a few months to complete. These synthetic stones can be found in doublet and triplet form in market. Doublet Opals are created of small slice glued with silica material, iron or glass stone.