What Is An Opal Doublet?

by Beth
(USA)

Opal Doublet

Opal Doublet

Question: Hello! Your opal creations are really lovely. I have a question. I notice that you describe some of your stones as doublets.

Others are not so named, but in some of your descriptions of your products, you indicate that you bond Solid Opal to a backing.

Do you then consider the latter to be a doublet?

I confess that I am wondering about this because I own an older Australian opal, that puzzled the experts who examined it. It is bezel set in 9k and almost certainly was created in Australia probably earlier in the 20th century.

After microscopic examination is appeared to be a face opal that was bonded to a thinner rather clear opal backing. It probably was produced before commercial doublet production was widespread.

I was just wondering if such stones, which seem to have some similar production characteristics to the opals that you create, are considered to be doublets, or possibly regarded as something else?




Answer: Thank you Beth for your question and interest.

Well, your opal certainly poses an interesting subject I must say.

When I first began cutting opal as a young man I used to be fascinated by opal's early history and the miners themselves, they were an intriguing lot that's for sure but I also read about early experimentation with opal doublets and the like.

Some used to experiment with tree resin for bonding (the trees in those regions were very tough) with joining the slice of opal to a backing (probably clear opal potch or similiar) using the tree resin, baking it for awhile in an oven then letting it cool and the resulting bond may have proved quite strong.

Developments in the 1950's and 1960's with new bonding epoxies certainly revolutionised the whole bonding process!

But to answer your question;

Once an opal is affixed to another stone or backing, it would always be classed as a doublet, (most doublets usually consist of a thin slice of opal attached to a backing to give it strength and as you say, often highlighting the colour,)

However, in some of my pieces the opal is quite thick enough to be classed as solid opal if left unattached.

When the opal that I use forms the full top half of a piece, I am actually using solid opal as a primary in my piece, but technically, it would still have to be classed as a doublet. :-)

Regards/Peter

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Ethiopian Opal
by: Cherie

Thank you for responding to my questions. I was pretty sure it was a solid opal with the polished sandstone attatched, especially since the sandstone part is thick and a bit uneven all the way around. However I do have one last question please ...

If an apoxy type substance had been adhered to the bottom of the opal would you still be able to see thru it and would it be that sandstone color?

Ethopian Opal
by: Anonymous

Thanks for your first answer. I have one more question please ... The opal I am referring to is a 8.00 ct oval stone measuring 20x11 mm.

The stone is fat and has a very high dome with amazing color. The bottom of the stone, which I am assuming is sandstone, is also highly polished, oval shaped, with a dome as well. The sandsone part is not even all the way around.

When the stone is held on it's side, where the color and the sandstone meet, you can see right thru the colored portion (like a gelly opal). When I hold the stone up to the light, no matter top or bottom, you can see my finger thru it.

So my question is, based on all the information I have given you .... are you saying you think this is a sold opal? Thank you

Reply on Ethiopian opal
by: Opals-On-Black

Hi anonymous, thank you for your question…As a rule, once an opal is made into a doublet one cannot see through the stone due to the black backing behind the opal.

The ethiopian opal you have purchased sounds very much to be a solid opal, natural sandstone adhering to the back of the stone is quite normal in some cases depending on how it has been cut.

Opal doublet
by: Anonymous

I purchased an ethopian opal a while ago. The sandstone is still attatched to the underside of the stone. It has been polished and is smooth just as the top is. My question is ... can you see thru a doublet when held up to the light? I see my finger right thu it.

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