Opal is hydrated silica and an amorphous mineral. In its’ natural form, Opal consists of closely packed aggregate spheres of silica as silica oxide, and water in varying amounts up to 15%. These spheres are arranged in a series of layers allowing light to pass through, defracting at specific points, creating the play of colors that attracts us to Opals. The larger the spheres, the more vibrant the colors produced. Referred to as “as common opals”, are those which lack the colored sparkle of the “precious opals“, though both are used in jewelry.
Lab Created Opals have found their rightful place in the World Gem Market. there are different references to these Opals including synthetic, simulated, and mosaic.
Synthetic Opal: is created in a Lab, but its’ properties, chemical, optical and physical, are identical to that of a naturally occurring Opal.
Simulated Opal: is also created in a Lab, and is optically identical to natural Opal, but does not have the same physical and chemical characteristics.
ALL varieties are quite beautiful! The simulated/synthetics are much hardier than their naturally occurring cousins, not so subject to temperature change, drying out, cracking or crazing. They can be, however, as expensive as the natural Opal, due to the long growing process (up to 2 years!). So, unless you are buying for investment purposes, find the stone you LOVE, and don’t worry too much about the How (or Who) of its’ creation. Enjoy it simply for the pleasure it brings!