12.37 CT Natural Australian Lightning Ridge Opal Solid
Product Details Gem Type : Rainbow Opal Weight : 12.37 Cts Size : 13.8mm X 17mm X 3mm Shape : Square Cushion Clarity : Opaque Color : Rainbow Color Treatment : None Origine: Australia Description: Product Details Gem Type : Rainbow Opal Weight : 4.75 Cts Size : 14mm X 8.9mm X 1mm Shape : Oval Clarity : Opaque Color : Rainbow Color Treatment : None Origine: Minatabie, South Australia Description: Description: Characteristic and its relative softness with a rating of 5.5 to 6.5 makes opal quite easy to identify and distinguish from other gemstones. Unlike other gems with play of color or iridescent effects, opal also exhibits 'opalescence'. Other iridescent stones do not display this pearl-like bluish color effect that appears to glide across opal, but instead, will usually show color that will abruptly appear, disappear and then reappear, depending on the viewing angle. The most important deposits are located in Australia. Around 95 percent of the world's supply of white precious opals are mined "down under". Famous deposits in New South Wales are at Lightning Ridge and White Cliffs, in South Australia at Coober Pedy and Andamooka. Various deposits are also found in Queensland. Opal can occur in many colors including white, colorless, pale yellow, pale red, gray, brown and black. Diffraction can cause flashes of any color of the rainbow which can be seen in opal's color play. Yellow, blue and green are most common, whereas violet, red and orange are the rarest colors seen through play of color. They are often cut en cabochon and depending on the opal color bar, it may be cut with low or high domes in order to maximize play of color and adularescence. Opal can also be faceted, most often seen with 'fire opal'.