Australian Black Opal Ring set in 750 18K White Gold 0.95 ct with 6 Diamond Total Weight 0.2ct Classified by the Opal industry as Natural Opal Type 1 - Light (or Light) Opal is defined when the Opal is presented in one piece in its natural state apart from cutting or polishing, and is of substantially homogenous chemical composition and has a N7-N9 Body Tone. Light Opal is found in Coober Pedy in South Australia and is also found in more limited quantities in Andamooka and Lightning Ridge. Natural Australian Light Opal is pure natural Opal without any internal impurities and displays untreated natural colour. (Ethiopian Opal often looks like Light Opal however Ethiopian Opal is treated with chemicals, dyes and smoke to give the colour. Australian Opal is completely natural and far more valuable). Natural Gem Light Opal often displays Pinfire and Rolling Flash Patterns, but can also display the rare and porecious harlequin pattern. When a Light Opal is transparent it is sometimes called Light Opal. This Opal does not however have a crystalline structure, and is not synthetic but pure natural Opal without any internal impurities and displays untreated completely natural colour.