Are black opal nobbies the most difficult to cut and polish?

2 barred nobbyWe all know that Lightning Ridge black opal is some of the best in the world. Unfortunately, along with being the best, it is also the toughest to find, but once you have been lucky enough to find a gem, there are some difficult decisions. The piece is then sent to the opal cutter to do the hard part of figuring out how to attack a color bar.
Cutting and polishing are one of the most challenging and time-consuming parts of the whole opal experience. Of course, you could go hard and go straight for the color bar, but this could mean you are making a big mistake and losing big $$$ as every carat counts.

This piece in the picture is one of the toughest to figure out. It is over 100 carats and has the best color on the top of the stone but has a second larger and solid color bar under it. Hmm, what to do?

Here is the question we opal cutters ask ourselves every day. Should I sacrifice the better color on the top of the piece for the more significant but greener bar below? You can see the lovely color bar hiding under the sand on the right in the image and the solid orange color on the top of the piece on the left.

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This is a problem that we encounter as opal cutters every day when it comes to nobby opal. Especially tough when the piece is worth around $50k. Any slight or wrong move, you could be losing thousands. And to add fuel to the fire, there is sand in the piece that we need to avoid. This piece has been studied for weeks, and now we are deciding what to do.

The miner and I came to the same conclusion. So next, slice the color bar off the top in between the first and second color bar. This is the most challenging part of it as the slice needs to be precisely where we have marked it out, so both color bars are untouched, and the potch is thick enough for a nice black back to keep the opal a black opal.

Unfortunately, we still have not decided what to do, but once the decision has been made on what to do, I will show you the results later.

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2 thoughts on “Are black opal nobbies the most difficult to cut and polish?”

  1. Personally I feel that I would cut a freeform stone. I think working on this gem would require a steady hand, a dentist drill and the removal of what appears to be a close to the surface inclusion sitting on a potch bar which could also be removed. Diamond John F.G.A.

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  2. I do know the feeling as I have one not on that scale but still a very nice opal and mapping it out and following it thru is more stressing than any other part, even if you free form it the cut has to honor the opals best, in my humble opinion

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