Ribbon Ring Lab Comparison

[Ribbon Ring]

 

[Ribbon Ring]

This might be a better quality:

 

[Ribbon Ring]

Some of the interesting things about this:
- about 75% of the diamonds rated by "Other" labs are in the near colourless category (G,H,I,J)compared to 53.3% for GIA and about 60% for AGS
- the top three for "Other" Labs are colours H, I and J, accounting for about 60% of their diamonds in this survey
- the top three for GIA and AGS are colours F, G and H, accounting for 50% of GIA diamonds in this survey and 2/3 of AGS diamonds

From the numbers, there doesn''t seem to be any indication that any of the labs are being soft at category margins. That is, there doesn''t seem to be indication that labs are being soft with G diamonds and giving them a rating of F, or K diamonds a rating of J. If they were, you should see an usual jump of some sort at F and J.

It does appear, however, that wholesalers are somewhat more likely to send their diamonds to "Other" labs when they are lower on the colour scale. AGS doesn''t have much of the market share, but wholesalers are somewhat more likely to send their G diamonds to AGS then other colours. And GIA is by far the most popular lab.

 

[Garry H (Cut Nut)]

I think your conclusions relate more to marketing than anything to do with labs.

 

[Ribbon Ring]

I'd say you're both right and wrong: wholesalers seem to have a slight bias for certain labs that is probably affected by marketing decisions.

 

[stone-cold11]

But you do not have access to the entire inventory of diamonds of the US much less the world, so how can you make that conclusion? What you have here is only vendor who use pricescope and uploaded some of their inventories, BN do not even upload their entire inventory here.

 

[Ribbon Ring]

I understand that. It''s nothing more than what it says it is, a survey of the Pricescope database.

 

[jet2ks]

Yet in your above post, you draw several conclusions about labs and grading.

From the numbers, there doesn''t seem to be any indication that any of the labs are being soft at category margins. That is, there doesn''t seem to be indication that labs are being soft with G diamonds and giving them a rating of F, or K diamonds a rating of J. If they were, you should see an usual jump of some sort at F and J.

This is definitely a conclusion you have drawn from incomplete data. You make the assumption here that every lab is getting the same statistical spread of colors and clarity, which just isn''t true. Wholesalers and cutters have a very good idea of what rating a stone will get from each lab and send it to the one that makes the most sense from a financial and marketing perspective, as Garry pointed out.

 

[Ribbon Ring]

Wow, Jet, you need to read what I wrote again. If I had written, "You can therefore conclude that the labs are not being soft at the margins" then your statement would be correct. But I didn't write anything close to that. First, I qualified that the statement is only based on these numbers, so I am being very clear that other numbers may be different. Second, even having stated that it is based on these numbers I only went so far as to write that there does not seem to be any indication. I definitely did not state I have drawn a conclusion; indeed, I never used the word conclusion. I certainly stand by what I did write, though: From the numbers, there doesn't seem to be any indication that any of the labs are being soft at category margins. And I stand by it because its true, based on these numbers there doesn't seem to be any indication of this. I find that interesting and plan to look at other databases to see if this continues to hold true. I have no intention of looking at all the diamonds in the "world", though, nor will that be necessary to eventually make a conclusion. I also want to look to see if anything interesting can be seen when the data is organized by clarity.

 

[risingsun]

Could you introduce yourself and tell us why you are posting this information? Thanks.

 

[Garry H (Cut Nut)]

RR the data bases almost totally miss the second tier labs - diamonds with those reports are almost entriely sold in B&M stores.

Your intentions are good, but I too stand by my first post.

 

[Ribbon Ring]

Good point, Garry. I''m going to do the same thing with some other databases, to see what comes up. I expected to see lower graded diamonds being sent to EGL, which this data seems to indicate. But I also expected to see some sign that G diamonds may have been fudged to F; but I don''t see any indication of that from this data. I am definitely going to go through more databases over the next week.