The doublets are made from selected flakes of the seam opal rough ground flat on what will become the bottom side. Once flat it is glued to a thin slab of black jade using epoxy which has been colored black. When dry and cured the excess backing is sliced off close to the opal using a thin blade diamond saw and the approximate outside shape of the opal is ground by hand on a diamond grinding wheel. The doublet is then mounted on a dop stick and the edges and top surface are sanded and polished using a series of diamond grinding wheels. The final high polish is achieved by polishing the opal (still on the dop) on a flat lap with Cerium Oxide slurry and then on a buffing wheel with polishing rouge. Once completed the opal is sanded thinner on the flat lap to an appropriate thickness.
You can see in the top two photos that the precious opal is a thin section glued to a thicker piece of black jade, while the bottom two photos show a nice gray base opal almost, but not quite, thick enough to stand on its own as a 'solid' opal. It is backed with a very thin piece of black jade to bring it up to proper thickness. Too bad too, because doublets are worth about 15-20% what solid opals are worth. In fact, when evaluating a doublet all it's qualities of body tone, brightness, color saturation, pattern, cut, carot weight and so forth are all judged as if the opal were a solid and the price then slashed by 80-85% to arrive at the price of the doublet. In other words the bottom opal is valued at $250-$500 retail if a solid or about $75 retail as a doublet. I have the opal priced at $45 wholesale as a cutter to a jewelry artisan.
Stay tuned. It makes sense to post a series of photos showing the steps I have described above. Then we will talk about evaluating the price of opals. Jim ...
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