Joined: Wed Oct 17, 2012 12:20 pm Posts: 108 Location: Cape Town S.Africa
Aquamarine heating and emerald oiling. Can anyone tell me how I can tell if aqua has been heated or not? An old post by Barbara B says that heating totally removes the green component. I assume from that,that if there is a green component,the material has not been heated.But,what if the aqua is naturally blue anyway?How would I know if it is unheated?I have about 17000cts[cut] from Mozambique,collected over a few years, so it would be very helpful to know.I don't believe the miner or cutter have the facilities to heat the material,but wouldn't want to claim "unheated" if it isn't. While I have your ears[eyes],I would also be grateful to ask about emerald oiling.I have 2600cts Sandawana emerald that I believe is untreated.Obviously,in this case,I can get a decent Lab. to test for me.But,if the cut material has no surface cracks[and a lot of it is in this condition],does it mean the material is unoiled,as there would seem to be no reason to do so? For material that does have surface cracks,would I be able to take photos and then compare to the same samples that have been agitated in acetone or benzene or whatever to see if the clarity changes? If some material has been oiled and I then "de-oil" it with a solvent,would it then be ethical to say it is "unoiled".Thanks
Post subject: Re: Aquamarine/Emerald heating/oiling
Posted: Tue Jul 28, 2015 7:11 pm
Platinum Member
Joined: Tue Jun 03, 2008 4:40 pm Posts: 2667 Location: South Dakota
It's generally an accepted understanding by the trade, that most emeralds are oiled or will be at some point. If you clean the stones in solvent then I see no reason why you can't call them "unoiled" There are some folks on here who deal with lots of emeralds that could give you more insight than I can.... As far as the aquamarine....just assume it's been heated. You only need a little furnace to heat stones so it's well within the realm of the "miner/seller" having access to the facilities. Regardless, it doesn't matter where in the world you are, people still send stones for treatment to foreign countries and have them shipped back for resale from their home market. Most in the trade already know most aquamarine is heated...it's one of those givens...especially if no green is present. Saying it's "heated/unheated" with aquamarine is really a moot point, unless you have a specific buyer(s) who buys only those kinds of stones.
_________________ MrAmethystguy ~ Some jokes just fluorite over my head!
Post subject: Re: Aquamarine/Emerald heating/oiling
Posted: Wed Jul 29, 2015 3:05 am
Valued Contributor
Joined: Wed Oct 17, 2012 12:20 pm Posts: 108 Location: Cape Town S.Africa
Hi Jason.Thanks for the reply,but I do have an important potential customer who insists on no treatment at all and, as you indicated, he does have a big problem sourcing unoiled emerald.Being Sandawana emeralds[Zimbabwe] and considered in the 1960's until the 1980's to be the finest emeralds available,especially in smaller sizes,they are very difficult to source[I am just adding these comments as a matter of interest]. The mine has closed some time ago and I got mine from artisanal miners. Most of the small ones are so clean and free of surface cracks that I don't think oiling would have been worthwhile anyway, but would love to be sure. If someone can put my mind to rest regarding aqua with some green being unheated,I would really appreciate confirmation of this, as I can then just select true aquamarine colours and be confident that they are unheated.
Last edited by raygem on Mon Aug 03, 2015 10:17 am, edited 1 time in total.
Post subject: Re: Aquamarine/Emerald heating/oiling
Posted: Thu Jul 30, 2015 3:06 am
Valued Contributor
Joined: Wed Oct 17, 2012 12:20 pm Posts: 108 Location: Cape Town S.Africa
Yeah, Barbara.I realised that after I posted about the first error, but didn't want people to think I was illiterate by posting another correction.Thanks, I won't make the same mistake again.
Post subject: Re: Aquamarine/Emerald heating/oiling
Posted: Thu Jul 30, 2015 1:18 pm
Site Admin
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
LOL....My name is Barbra. Everyone from my bank, IRS, DMV and co-workers think I have made a careless error and correct the spelling of my name to Barbara. It's OK.
"Yeah, that's the girl. Was her name Brahbrah? No, I think it was Barbara. Her name was Brahbrah. It was Barbara, there's no such name as Brahbrah. It's Brahbrah." -Flight of the Conchords
Hehe. Raygem, if you are interpreting me as making fun of you, it is a misinterpretation. It's just a quote from a funny song about mishearing the name "Barbra." Nothing more to read into it. For future reference, though, you can edit your posts pretty easily after the fact to correct small errors (there is an icon below all your past posts). Most of us make the Barbra/Barbara mistake at first, but we just hid the evidence
Joined: Wed Oct 17, 2012 12:20 pm Posts: 108 Location: Cape Town S.Africa
Barbra Any of you are very welcome, but I am a bit far from where the gemstones are found. But where we have a cottage on the West coast,just a bit further up they are sucking up diamonds from the sea bed.A friend of mine was a diver doing that.Apparently, they get a lot of zircon that,at first sight,looks like diamond, but then toss it onto a pile.as trash.I enquired about "taking them off their hands", but I think they are worried that some diamonds might be tossed onto the pile deliberately for sorting later!! Cheers Ray
Post subject: Re: Aquamarine/Emerald heating/oiling
Posted: Sat Aug 01, 2015 9:34 am
Gemology Online Veteran
Joined: Sat May 22, 2010 2:51 am Posts: 755 Location: South Africa
Ray, I have cut some zircons from a South African diamond mine - Monastery - a beautiful light honey colour. Some went a pale salmon pink on gentle heating but reverted on cooling. But I haven't (yet) come across any coloured gem material that survived the trip down the palaeo-Orange/Gariep River. I too have a cottage up the West Coast. Perhaps we should go dig some diamond trash heaps together
Post subject: Re: Aquamarine/Emerald heating/oiling
Posted: Sat Aug 01, 2015 10:13 am
Valued Contributor
Joined: Wed Oct 17, 2012 12:20 pm Posts: 108 Location: Cape Town S.Africa
Hi Duncan The gravel was picked up in Hondeklip Bay.I could have been mistaken and it could have been garnet.Wherabouts are you up the West coast? Our place is on Verlorenvlei [Elands Bay ].I used to get the large,smooth pebbles at Graafwater-excellent for the garden and plant pots etc.Sold by the bakkieload,but I think it is closed now. Apart from you,it is strange that I haven't had any sensible answers to my 2 questions, but have sent parcels to my potential buyer, who will get them certified.The emeralds I sent to EGL [I think Jeremy did the grading when he was there] had no evidence of treatment,so I am fairly confident they are untreated. Unfortunately, for overseas sales, customers prefer GIA certificates or similar, so I can't get them graded locally.
Post subject: Re: Aquamarine/Emerald heating/oiling
Posted: Sat Aug 01, 2015 11:48 am
Valued Contributor
Joined: Wed Oct 17, 2012 12:20 pm Posts: 108 Location: Cape Town S.Africa
Have been doing some checking. There seems to be a lot of zircon in that area. The Namakwa Sands operation is up there on the coast opposite Vredendal.They produce huge quantities of zircon, but this is in the form of sand,so I don't know if any sizeable crystals end up there as I suppose they are mostly ground down by the wave action.Wracking my brains[also ground down, but not by wave action!], I definitely recall it being zircon. Anyway, let's hope we can argue the point over a beer sometime soon.
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