Who shall I send potential black opal to?

[theredspinel]

In the UK?

I want to be assured of its Australian origin and the fact that it's not treated Ethiopian opal.

Thanks so much for any suggestions.

 

[theredspinel]

Bump! Before it gets lost into the abyss

 

[MollyMalone]

My first thought was the AnchorCert lab, which is an offspring of the Birmingham Assay Office, but upon further exploration of the web site, it looks as if origin reports may be limited to rubies, sapphires, and emeralds. They don't accept stones directly from consumers; you'd need to submit the stone via an AnchorCert retailer:
https://anchorcertgemlab.com/find-a-retailer/find-a-retailer

But perhaps the lab would tell you whether you should even bother taking the stone to an AC retailer -- and if they don't issue origin reports re opals, perhaps they would suggest an alternative lab. Here's their contact info:
phone
https://anchorcertgemlab.com/contact-us/telephone

email form
https://anchorcertgemlab.com/contact-us

 

[MollyMalone]

P.S. Gem-A, the Gemological Association of Great Britain, used to offer a service whereby stones could be sent to/dropped off at their headquarters & they would handle the delivery to-return from GIA's lab in NYC. And because they were doing this in bulk, it cost less money than what you would have to pay on your own to get a stone to-from NYC. But that service appears to have been discontinued, I'm sorry to say.

 

[theredspinel]

P.S. Gem-A, the Gemological Association of Great Britain, used to offer a service whereby stones could be sent to/dropped off at their headquarters & they would handle the delivery to-return from GIA's lab in NYC. And because they were doing this in bulk, it cost less money than what you would have to pay on your own to get a stone to-from NYC. But that service appears to have been discontinued, I'm sorry to say.

Oh dear.

Thank you for your above information I forgot to mention in the opening post this opal is mounted on a ring.. does that change anything?

Thanks again I really appreciate it!

 

[MollyMalone]

Oh dear.
Thank you for your above information I forgot to mention in the opening post this opal is mounted on a ring.. does that change anything?
Thanks again I really appreciate it!

Found an AnchorCert page where they say they will examine stones mounted in jewelry -- but it's also where they make clear that assessment of origin is limited to emeralds, sapphires, and rubies:
https://anchorcertgemlab.com/about-us/anchorcert-gemlab
Although they may be able-willing to say whether or not it's a true black opal.

SafeGuard is the appraisal arm of the Birmingham Assay Office, so obviously will issue an appraisal report -- and you can, but need not, give the ring to one of the designated retailers; you can submit the piece yourself to SafeGuard & they also host appraisal event days at UK jewelers.
https://safeguardvaluations.com/about
https://safeguardvaluations.com/services/valuations-direct
So how about contacting them to ask if they will do what you're hoping for, or at the very least, exclude the possibility that it's one or the other. Have no idea what the difference in fees charged by AnchorCert and SafeGuard might be; I'm not seeing a fee schedule posted by either outfit.

But let me ask you this: is the opal mounted in such a way that you can see the back (and maybe also the sides) of the stone clearly? If so, posting those pics here -- in a new post under a new topic heading -- could garner some informed responses that might be helpful to you in deciding whether to spend money to pursue this further.

Plus, I'd love to see the ring

 

[jordyonbass]

Thank you for your above information I forgot to mention in the opening post this opal is mounted on a ring.. does that change anything?

It depends on how it has been set; if the edge and/or back of the stone can't be seen then there may be no way of telling whether it is a doublet made with natural Opal or a genuine, solid black opal.

 

[Bron357]

Post up a photo.
Maybe we can offer an opinion ie a don’t think so or a probably so.
Yes, if set, Black opals can be doublets if you can’t see the back. I will be finding out in due course re- mine as opals have to be “unset” for soldering.
The earrings are currently screw on and I need this changed over to wires.

 

[theredspinel]

Thank you Molly you continue to be invaluable. I will follow up all those links you've kindly given (young kids, a job, I just need ONE moment to myself to fully check out your links)!

The back of the ring is open, im not thinking it's an doublet or anything... My main fear is it's a treated Ethiopian.

I've been looking at black opals for years and something.. I dont know... it's too perfect. The shape, it's even got double sided colour play, seems bright, great mounting etc.. for the price it's too perfect.

Ish.

Doesn't have top brightness I'm sure. Also the stone needs rotation for different parts to light up - it's about 10% of the stone lights up in any one go if that makes sense. It's hard to explain without pictures!

I will post a pic I promise but don't want to risk it yet.

Great to "see" you here jordy really happy to have your input. If I purchase it and I do the soak it in water for a day or 2 test.. If nothing leaks are there other at home tests I can do?

Hiya bron amazing earrings. Fingers crossed for you, my prospective opal has no where near as nice a pattern.

 

[Bron357]

Hmmm, my limited experience with solid Australian opal is that with black opal the colour play is “there”in a static position, the colour is up to the surface and throughout. Sure the colour moves around as you move the stone but in a stationary position it still has lots of colour. Crystal opal, is a bit different, it is more translucent tends to show colour as it moves. It’s a different look.
I also have some Ethiopian opal, it’s similar to Australia crystal opal except the background is a sort of yellow brown colour and you do need to move it around a lot to see the colour play.
And if it gets wet, the colour play pretty much disappears for a few days / a week until it sort of dried out again.
Real Black Ethiopian opal exists, it’s rarer, but because the ordinary variety is hydroplane, it can literally absorb black dye into the gem, so unscrupulous people are simply and easily dyeing ordinary Ethiopian opal and pretending it’s real black opal. As far as I know, no type of Aussie opal can absorb dye.
Hope it all turns out ok for you.
With me, doublet or solid - no problem, they are just so lovely I don’t care!

 

[theredspinel]

Ok I've just heard back from the seller and he's willing to send it to GIA for me (at my cost). Take this option?

What can GIA tell me?

Continued thanks

Hahaha bron I wish I could be like that. No..I've got the coloured stone purist DNA...:roll

 

[theredspinel]

It depends on how it has been set; if the edge and/or back of the stone can't be seen then there may be no way of telling whether it is a doublet made with natural Opal or a genuine, solid black opal.

Another question: do all black opals need to have potch on the back?

This opal does not. But it is very very dark, greyish bluish black.

Perhaps it's a dark crystal opal??

 

[jordyonbass]

Another question: do all black opals need to have potch on the back?

This opal does not. But it is very very dark, greyish bluish black.

Perhaps it's a dark crystal opal??

Not necessarily, some stones are translucent when held up to light but the body tone is so dark that they are known as a 'Black-Crystal' or as you have stated 'dark-crystal'. In my book that is still a black opal, it's transluscent instead of completely opaque but still has the defining black body tone. The stones in my display picture are a couple of Black Crystals as well

 

[jordyonbass]

A test you can do to ensure it hasn't been dyed is to soak it in high proof alcohol for about 5-10 minutes, if it has then the dye will run into the liquid and discolor it.

 

[Bron357]

Another question: do all black opals need to have potch on the back?

This opal does not. But it is very very dark, greyish bluish black.

Perhaps it's a dark crystal opal??

Australian black opal is normally found in a “thin” strip so most do have a potch back. But you have to take care and actually check the edge (like a diamonds girdle) just to make sure it isn’t a doublet (cos a doublet is an even thinner strip of opal glued onto a potch back)..
I checked Mr U tube, apparently if you soak the opal in water Overnight the dye will start to run out and the colour play will disappear (until the water evaporates) if it’s an Ethiopian opal and/or dyed.
Aussie Black opal will ever lose it’s colour play after being in water. Let alone have a dark substance ooze out.
You can do this simply yourself, depending on your vendor and payment method, if it is not genuine Australian black opal you should be able to return it as “not as described. Use PayPal and/or a Visa card so you can do a charge back if you’ve been misled.

 

[theredspinel]

Thanks so much both.

Worth sending it to GIA or just buy it and do the alcohol home test?

GIA means I'd be waiting at least a month.... who can handle that!

 

[theredspinel]

Not necessarily, some stones are translucent when held up to light but the body tone is so dark that they are known as a 'Black-Crystal' or as you have stated 'dark-crystal'. In my book that is still a black opal, it's transluscent instead of completely opaque but still has the defining black body tone. The stones in my display picture are a couple of Black Crystals as well

Can you have a double sided colour play *opaque* looking black opal??

 

[jordyonbass]

Can you have a double sided colour play *opaque* looking black opal??

Yes that is possible, rare but possible. A lot of cutters would consider slicing the rough straight down the opaque potch to get 2 stones - so it's not something very commonly seen.