October 24, 2021

Q&A regarding doublet, vs Inalid doublet, vs black opal, etc..

Q&A regarding doublet, vs Inalid doublet, vs black opal, etc..

Below is a conversation we had via email with a client about the origins, nature, manufacturing and classing specifics that are relevant to most of our pieces. Their excellent, comprehensive questions deserved thorough answers. Please see below for some FAQ & A about some of our products and processes....


Q:    So, I do have a few more questions sorry. I was doing some more research because I am trying to understand the price differences between the pieces and to make sure I understand what I am getting. To be honest, I was a little disappointed to read that a "doublet" is actually just a thin slice of opal adhered to a black backing to give the appearance of a solid vibrant black opal. So just to clarify, are the opals you use, white or black? And are the pieces that are referred to as "inlaid doublet" more valuable / higher quality than the ones that are just called "doublets"? I’m I thinking they are because then one can't really tell they are doublets, but I want to confirm :). And lastly, what drives the difference in the price per carat of opal that you list in the ad? I've seen them range from $350-$500-$900 (per carat up at the top you usually put this)?

A:  We use Coober Pedy opal that we mostly mine ourselves, the opal for the most part starts out as either ‘light based, white based or crystal opal and occasionally dark or ‘semi black’ opal rough.

Often we use crystal ‘shell skins’ as this is one of the most common forms of opal that I have found for years mining in Coober Pedy because they are something I can hunt for that has been missed (less obvious to previous miners) and they often have the most stunning colour of all, an example is E17, 

'Drill set' doublet with 14k gold bail.

this was made from a dark crystal opalised shell skin (ancient opal replaced Cretaceous sea shell fossil) we mined on the Old 15 Mile, it is a bit too thin to make a solid opal from so we clean it right up to make a doublet. The result is as you say, giving the appearance of a stunning natural black opal, the thing is with doublets they are typically accepted in the opal industry as being valued at about 10% of what a natural solid black opal would be valued at, so say E17 was a natural black at 5 carats or would be around $1000 - $2000 per carat or more (sorry I’m not an expert in black opal valuation) but safe to say it would be 5k upwards.

Also, when we value ‘per carat’ we are only referring to the estimated weight of the light, or crystal etc opal layer, not the whole piece with the backing, Whereas a black or boulder opal ‘carat price’ applies to the whole stone. So as you say, it is a pity they’re not solid blacks or boulders, but it affords us and our clients the opportunity to deal with identically stunning opal at a fraction of the price, suffice to say we love doublets! But of course we want to be very clear about exactly what we are selling.

An ‘inlaid doublet’ is similar to a doublet in that it has a boulder backing but is not a solid Queensland boulder opal, but it is superior in that it is inlaid, and fully encased in gold making it relatively impervious to moisture and grease etc.Inlaid doublet shell skin with diamond bail.

A pre cut doublet is set differently, with a rubbed over bezel or claws.

Below is a classically set solid opal with a rubbed over bezel.

A classic style 'rubbed over' bezel.



Q:  My husband’s vote is to take you up on your offer of leaving E17 alone and not worrying about it not being encased in gold. Would you say you sell many that way… not inlaid in gold? And people are happy with them? Or more that are inlaid in gold and thus avoiding the seal issue and the sort of odd look of a stone on the back of the pendant?


A:   With the doublets, our quality processes are very strict and they are very durable without the gold bezel, it’s really just a matter of personal taste, but we have had hundreds of happy customers with just drill set doublets, the only issue arises when someone assumed it was gold wrapped and then found it wasn’t. As you said, educating the consumer is valuable! 

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