Vivid Boulder Opal, Queensland Australia origin. The silica material of this type of Opal forms in thin layers in the cracks and fissures of large underground ironstone boulders, and usually is so thinly layered that that it cannot be extracted without its ironstone backing; hence the name Boulder Opal. The handmade Gold ring setting for the above Vivid Boulder Opal is completely open at the rear of the gemstone, allowing a view of its natural roughish ironstone backing.
It is often the case with this type of Opal, due to the thinness of the layering, that the ironstone protrudes through to the surface of the gemstone, and the work of the cutter is then to maximize the opal surface and minimize the ironstone matrix. The above Vivid Boulder Opal is of clean face, without any surface ironstone matrix, and has excellent play of colour across the entire gemstone surface, from blues to red embers, from a scintillating green to burnt orange; it is a very fine example of a clean-faced Australian Boulder Opal.
The ring setting, clean and simple in form, is handcrafted in solid 14ct Gold, stamped 585, signifying a pure 999 Gold content of 58.5%. (9ct Gold, 375, represents 37.5% pure Gold content; 18ct Gold, 750, 75% pure Gold content.)