Find your diamond
Find your jewelry
shape
carat
color
clarity

GCS Certification?

babs23r

babs23r

Brilliant_Rock
Joined
Dec 20, 2012
Messages
739
HI,
I was browsing on Etsy and came across an OEC for too good a price. I asked about certification, and the vendor who says he is located in London said he could get a GCS certification....???
Too good to be true isn't, right?
 
Yes, stick with GIA stones to be absolutely sure about what you're getting.
 
yes, thank you. I thought so.
 
Well not necessarily. If it’s ungraded, assume a colour grade at least 2-3 shades more tinted than is claimed and probably 1-2 grades worse in clarity.
If even then, it’s a too good to be true price AND you love the faceting AND there is a good return policy that you are able to take up, I would take a punt on it. I’m assuming btw that the seller is happy to provide video and additional photos in natural light, face on, white background etc upon request ie they’re not acting shady when you ask for more information.
Or I’d post it here for feedback/opinions.
 
:appl:You make sense, thanks . I will ask for pictures and see what happens.
 
I just asked the vendor to take pics and he said he would do it tomorrow. Thanks for the advice. Will keep you posted!
 
Excellent! if you post up the claimed specs and pics when you get them, we can probably find comparisons to the likely stats and work out if the price is really good or not. And also we like to see pictures of diamonds whenever possible!
 
icm_fullxfull.136543480_o8izgp2lwn40o4c004o4.jpg
 
I would guess it is an S/T color
 
We can't grade a diamond's color or cut quality from a photograph. It is sound advice to say an independent lab or appraiser is not the same as a GIA grading report, but you can't get such good advice about color from a diamonds in a photo. The yellowness of the diamond in the photo could be the lighting and not be a true representation of the diamond's correctly lit body color. If it looks that yellow in real life, in correct grading light, then it is not an "L" color but several shades darker.

It does look like a lively stone and might be well worth getting an officially recognized grading report.
 
Thank you all,
I'm going to let it go. Too yellow, and the price was TOO GOOD!
 
Have any of you heard of GCS certification? That was the lab he would send it to.
 
Is it chipped? If so you need to get it examined and repolished or even recut. I would not recommend leaving a chip hoping for the best with an expensive stone like that. There's too high a chance of ruining it.

Not all minor labs are sleazy, but you should assume guilty until proven innocent. One problem with OECs is that GIA will grade many of them as a poor cut modern round brilliant. Some vendors will not send an OEC to GIA because of that. But a good appraiser will be able to grade color and clarity accurately.
 
babs23r said:
Thank you all,
I'm going to let it go. Too yellow, and the price was TOO GOOD!
Click to expand...
Like PS Trade member OldMiner, I wouldn't consider that photo to be determinative. On my computer screen, it's showing up more as grayish-green (along with a blue facet) than yellow, so I imagine the photograph is reflecting environmental colors, not the diamond's own body. I don't know what "too good" a price is, but my casual observation would be (I've not been keeping spreadsheets on this) that old cuts in the UK do not yet enjoy the popularity currently seen here in the US, so UK asking prices are lower.
babs23r said:
Have any of you heard of GCS certification? That was the lab he would send it to.
Click to expand...
fyi: there is no GIA lab in the UK or anywhere in Europe. The Gemmological Association of Great Britain (Gem-A) used to offer a service whereby they would handle the insured shipping of diamonds, colored stones, and mounted colored gems between London and GIA-NYC for local jewelers at a discounted price, but Gem-A seems to have discontinued that facilitation of GIA grading.

Does the etsy vendor seem to deal primarily in estate/vintage/antique jewelry pieces with colored stones? Like GIA, GCS won't grade diamonds that aren't loose,
http://gcslab.co.uk/diamond.html
but my Google searches show that, e.g., the Sotheby's, Skinner, and Bonham auction houses in London & a number of dealers in such merchandise over there are use GCS for estate/vintage/antique pieces with colored gems; feel comfortable relying on GCS's opinion re treatment and provenance, e.g., unheated Kashmir sapphire, Burmese ruby that's not been subjected to any treatment.

Think I'd be inclined to have AnchorCert, a lab under the auspices of the Birmingham Assay Office, do a report on the OEC. Primarily because GCS doesn't make plain on their web site what they use to grade color whereas AnchorCert's web site informs the reader that it uses both a colorimeter & a GIA master color set.
http://anchorcertgemlab.com/about-us/diamond-colorimeter
But like AGS here in the US, its lab services are only for those in the trade & AnchorCert doesn't publish its fee schedule (basic cut and clarity report from GCS is ~$40). Plus, the etsy vendor in London can't walk the stone to AnchorCert (Birmingham is about 125 miles from London), so it's not surprising he hasn't volunteered AnchorCert as an option. You might consider negotiating with him the expenses attendant to getting an AnchorCert report.
http://anchorcertgemlab.com
 
Last edited:
I have been looking at etsy, and even the vendors in the US have really low prices on their stones/ rings, but no credible certification. Look at Allen Gleur. Beautiful items, but won't get a GIA certification...
 
Well, it seems you'd really be buying "a pig in a poke" when ordering from Allen Gleur because his listings often rely on stock photos. E.g., notice how these 2 listings show exactly the same ring:
https://www.etsy.com/listing/553578412/100-carat-old-european-cut-diamond?ref=shop_home_active_2
https://www.etsy.com/listing/551743936/old-european-cut-diamond-french-basket?ref=shop_home_active_7

And query whether ordering either of those would be deemed a custom order -- and therefore can't be returned for a full refund, unless they arrive damaged or "defective"
https://www.etsy.com/shop/AllenGleur?ref=condensed_trust_header_title_items#policies
-- because the ring would be made in your choice of metal in your ring size. (Not that it's unusual for custom jewelry orders to be final sales; that's par for the course. But unless he's willing to supply pics before embarking on making the ring, you're totally clueless as to which particular stone you'd end up with until you received the ring.)
 
Last edited:
I'm pretty sure GCS uses colorimeters or even spectrophotometers and not master gem sets.

See here: http://gcslab.co.uk/about.html

Plus, on the website: We think the only way to meet the challenges that arise in the current market is to work in the same way that large internationals laboratories. This is why we use the same protocols and the same equipment (FTIR, Raman, XRF, Digital microradiography, UV and UV-Visible-NIR spectrometry ...).

I once asked here on PS why everyone doesn't just use a colorimeter instead of an eyeball grading. The answer is that factors like cut can change the color grade and you wouldn't consistently get a match between eyeball grades and colorimeter grades. So if your goal is to compare to GIA you need an eyeball grade.

It seems GCS grades a lot of scary expensive antiques, the sort of thing people forge. For that you want something more sophisticated.
 
MollyMalone said:
Well, it seems you'd really be buying "a pig in a poke" when ordering from Allen Gleur because his listings often rely on stock photos. E.g., notice how these 2 listings show exactly the same ring:
https://www.etsy.com/listing/553578412/100-carat-old-european-cut-diamond?ref=shop_home_active_2
https://www.etsy.com/listing/551743936/old-european-cut-diamond-french-basket?ref=shop_home_active_7

And query whether ordering either of those would be deemed a custom order -- and therefore can't be returned for a full refund, unless they arrive damaged or "defective"
https://www.etsy.com/shop/AllenGleur?ref=condensed_trust_header_title_items#policies
-- because the ring would be made in your choice of metal in your ring size. (Not that it's unusual for custom jewelry orders to be final sales; that's par for the course. But unless he's willing to supply pics before embarking on making the ring, you're totally clueless as to which particular stone you'd end up with until you received the ring.)
Click to expand...
You are sooo right!
 
ChristineRose said:
I'm pretty sure GCS uses colorimeters or even spectrophotometers and not master gem sets.

See here: http://gcslab.co.uk/about.html

Plus, on the website: We think the only way to meet the challenges that arise in the current market is to work in the same way that large internationals laboratories. This is why we use the same protocols and the same equipment (FTIR, Raman, XRF, Digital microradiography, UV and UV-Visible-NIR spectrometry ...).

I once asked here on PS why everyone doesn't just use a colorimeter instead of an eyeball grading. The answer is that factors like cut can change the color grade and you wouldn't consistently get a match between eyeball grades and colorimeter grades. So if your goal is to compare to GIA you need an eyeball grade.

It seems GCS grades a lot of scary expensive antiques, the sort of thing people forge. For that you want something more sophisticated.
Click to expand...
I hear you. Only going to look for GIA graded or AGL USA graded stones.
 
ChristineRose said:
I once asked here on PS why everyone doesn't just use a colorimeter instead of an eyeball grading. The answer is that factors like cut can change the color grade and you wouldn't consistently get a match between eyeball grades and colorimeter grades. So if your goal is to compare to GIA you need an eyeball grade.
Click to expand...
For a rather different perspective on colorimeter use from Jonathan Weingarten (PS Trade member Rhino):
https://www.goodoldgold.com/diamond-colorimeter

Think it's worth noting at this juncture, @babs23r , that the same GIA lab won't always grade a stone twice the same way. And PS Trade member Wink (High Performance Diamonds), for one, has been expressing displeasure in the past 2 years about GIA's collective inconsistency, e.g,
Wink said:
GIA with multiple labs around the world is having horrible problems with consistency, while AGS with only one lab is much more consistent in both color and clarity.
Click to expand...
Wink said:
GIA now has many labs around the world and they are having serious problems with consistency, so while the likelihood of them being two color grades off is low, it is possible. * * *
Click to expand...
 
Thanks Molly! Great article.

They note that the colorimeter isn't useful for fancy shapes. That's because the various fancies just don't move the light the same way and the machine just isn't measuring the same way as the eye.
 
You must log in or register to reply here.
GET 3 FREE HCA RESULTS JOIN THE FORUM. ASK FOR HELP
Jewelry Blog
PriceScope-Concierge-Ad
Find prime cuts.
Top