Posted on Leave a comment

No potch, no worries!

What makes a Black Crystal Opal so unique?
I’ll tell you all about it as we cut and polish a piece of rare Black Crystal Opal rough this week from the Wyoming field in Lightning Ridge.

The phenomenon that is Black Crystal Opal

When you come across a piece of opal with no potch but is dark in body tone, this is Black Crystal Opal.
It’s quite a phenomenon as the darkness comes from a natural tint inside the opal rather than the potch found in a Black or Dark Opal.
When it comes to color on color, Black Crystal Opal is the epitome of beautiful color.
When you have flakes of gem color on top of each other with that 3D effect — Black Crystal is the best type of gem opal to display that kind of color.

The examination & process

While examining a piece of any rough Crystal Opal, you’re always looking for the ‘better’ side to cut and polish.
Which side has the least amount of sand and inclusions and the prefered color and pattern?
The bonus with Crystal Opal is that both sides have the ability to cut and polish well enough to produce a double-sided gem.

When I first examined this piece of rough opal, I had decided which side I was going to work on.
Once I took it to the wheel and started to clean up the opposite side, the color and pattern started to open up.
Now it seems I have both sides of that opal as a choice.
One side is showing a Cloverleaf Pattern and the other is Flagstone with a rich depth of color — could this be a double-sided gem?

Most of you are quite aware that I do love symmetrical shapes, so this will more than likely be an oval-shaped opal.
As I work the opal into shape, I keep an eye on any sand spots and fractures — all the while creating pleasing domes on each side of the gem.
Doing this as much as I can by hand will allow an easier and more precise finish off with the dopstick.
Even when an opal looks like a straight-forward cut, things like small fractures can give you grief when trying to achieve the perfect cut.

The results are in

We ended up with a gorgeous 5.47ct Black Crystal Opal.
A little smaller than I had anticipated due to a few sand spots and ridding the gem of any little side fractures.
With a lovely brightness of a 3 and a medium dome — you can find the final gem here.