Solid or Doublet Opal?

Solid or Doublet opal ?

Solid or Doublet opal ?

I recently bought what was sold as a solid natural cabochon Opal.

When I look at it the top has lovely flecks of orange green and red in it but if you look at it from the side you can see a line and the bottom of it isn't polished.

I read that a doublet Opal has a black backing but the back of this is the same background colour as the front, a kind of creamy colour.

Could it be a doublet Opal and if so what could the backing be?
Also how could it be sold as a solid natural Opal?

Sorry I only have the picture that was from the seller as I don't have a decent camera so the side and bottom arn't shown.


ANSWER:

Hi Heather,

Well, it is rather hard to verify the stone's credentials without seeing it first hand or a close up of the side of the stone.

A doublet opal doesn't have to have a black backing to make it a doublet - what makes a doublet is an opal having a backing to the stone.
(The backing itself may also be a slice of natural opal adhered to the Gem.)

In this case without seeing the gem, the line may be a natural colour line of the opal itself which would make it a natural solid but if there is a distinct join in the opal, then it could constitute being a doublet.

My best advice would be to inspect the line that you see with a strong magnifying glass, you should be able to tell whether the opal flow of colour is unbroken or if there is a distinct difference between the opal above the line and the suspected backing under the line.

Even run a sharp razor blade gently ( no, you won't hurt the opal) diagonally across the side, if the blade catches on that line, then there is a good chance that the stone is a doublet opal.

Hope this helps answer your question. Let me know how you go with this one.

All the best, Peter

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