Precious Opal is composed of minute uniform spheres of silica, which are arranged together in orderly three-dimensional grid. The spaces between these spheres contain silica in solution. However, in common opal, where there is no play of colour the spheres are varying sizes and are not uniformly stacked.
White light passes through the transparent sphere directly, but when it reaches the silica in solution it is deflected at angles. These diffracted beams of light may show all the colours of the spectrum or particular colours may predominate.
The colour emitted from opal is dependent on the size of spheres, which determine the wavelength. For instance, blue colours are evident where the spheres are smaller and, at the other end of spectrum, orange and red will evident where the spheres are larger. The intensity and brilliance of the colours are a result of the degree of uniformity of size and regularity of the gird.
Opal derived its name from “Opalus” which meant “to see a change in colour” The Ancient Romans popularised opals more two thousand years ago, when opals were found at Czernowitz, a mountainous region of Slovakia, was at that time apart of Hungary. Pliny the Elder wrote inaugural Natural History of the World, which was first published in 11AD. In this most important publication he wrote that opal was most highly prized and valuable of all gemstones in the Empire.
Where to buy opals in Sydney?
You can find the beautiful Australian Opals in our Sydney store, we are Australia’s largest Black Opal, Boulder Opal and Crystal Opal jewellery shop. We have the finest quality Opals at the most competitive price. Our have unset Opal stones, Sterling Silver Opal jewellery, as well as 18k gold and platinum Opal jewellery. We have the largest collection of Opal earrings, Opal rings, Opal pendants, Opal bangles and Opal bracelets in Sydney. When you consider to buy Opal Jewellery in Sydney, go to someone who specialises in Opals. At Cosmopolitan Jewellers, we only carry solid Opals and do not sell doublets or triplets. We are also licensed Duty Free.