Black or Dark Opal?

Black Opal or Dark Opal? Your guess is as good as ours.

We picked up this Nobby on our last trip out to Lightning Ridge. It came from a field where a patch of black opal was recently found, so our hopes are high. There is no indication that this nobby will turn black but stranger things have happened. All we can do is jump on the wheel and ease our way through the cutting process and asses as we go.

Does it turn black?

When inspecting the nobby with the Gemfish flashlight, there is something inside, is it potch or sand? We’ll start on a fine 500 grit sintered wheel and clean up the edges of the color bar. There are little hints of potch that may turn the opal black, fingers crossed! The more we work on it there more sand spots begin to appear. Due to the smattering of sand spots, my only option is to slice the opal and salvage the areas not affected by sand.

One turns to three…

Guided by the sand spots, we mark out each gem and head to the slicer. What was one opal with hopes of turning black is now three bright dark opals. As I work each one on the wheel, I am blown away by how brilliantly bright they are (definitely compensation for not turning black). If you took out the monetary value of the nobby cost, all three gems are beautiful opals in their own right.