Opal Cutting and Polishing
What is opal cutting? It probably does not occur to many people but opals sometimes require cutting just as diamonds do, to enhance their shape and look and even improve the reflective qualities of the opal.
As with diamonds, the cutter has to take into consideration a number of factors. Of course he wants to retain the maximum size of the stone by cutting away those areas that may have cracks or are rough. Usually a cutter will get a heap of opals, called a 'parcel' and out of these he will select those that will be enhanced the most by cutting.
An opal cutter will spend some time considering the cut as cutting too much off or incorrectly with drastically reduce the value of the opal. A diamond saw is used initally used for the cut and liberal amounts of water is used during the cut to reduce the risk of cracks and burn marks or pits, due to possible extreme temperatures, during the cutting process.
After the saw cut the cutter will adhere the opal to a stick called a 'dop stick' and then A series of diamond grinding wheels of increasing finess is used to polish the opal, remove saw marks and other imperfections.
The last action of the cutter is the polishing to ensure the best surface is enhanced. Serium oxide is used to polish the opal and this is done with a felt wheel with water to produce the beautiful finish so well know with opals.
Cutting and polishing opals is an art almost and requires great expertise and patience. Some opals, weight for weight, can be worth more than diamonds so the cutter has a responsible job.