TODiamonds
Shiny_Rock
- Joined
- Jul 27, 2019
- Messages
- 260
Generally around these parts I often read about how one should only trust GIA and AGS. I totally get it and if someone has the money, then they should definitely improve their odds of getting what they pay for by going with a top grader. However, from what I've seen, there can be fantastic IGI diamonds for much better value than GIA if you're willing to do the leg work. I think IGI is often unfairly completely dismissed on this forum (and the greater North American community at large).
In my research (before buying my IGI diamond), I came across a few interesting studies on IGI vs GIA. Rather than just take the commonly acknowledged view that IGI sucks, I wanted to find objective information. I could only find two studies but they seemed to support the idea that IGI diamond grading is reasonably consistent with GIA standards. I am sure these studies are not news to those of you experts on the forum
https://www.diamonds.net/News/NewsItem.aspx?ArticleID=43417
https://www.diamondscreener.com/edu...ification-labs-gia-vs-igi-grading-and-prices/
The first of these (and the more objective one in terms of methodology) was done by Rapaport in 2013. They sent 10 diamonds of varying sizes and specs to 5 grading labs. Completely anonymously. The results showed the IGI graded the diamonds practically identically to GIA, and both of those were statistically meaningfully more consistent and disciplined in their grading than the 3 labs (AGS was not part of the study). It would be interesting to know which IGI lab they sent the diamonds to, but that is not disclosed unfortunately.
The second study was performed by Diamond Screener (date unknown). They did a retroactive study by combing through James Allen and Blue Nile databases and finding diamonds that were dual-graded by IGI and GIA (n=37). While they work with a larger sample size than Rapaport, this one was less objective because I think all the diamondsThe results support the Rapaport study. In fact, they found they actually found that IGI was generally stricter on color than GIA. They were on par on clarity.
Both studies show IGI diamonds trading between 12-20% less than GIA diamonds despite the data. The results also support what several of the local experts here (Garry H, John Pollard among others) have been suggesting for a long time about IGI being reputable and sometimes even preferred in parts of Asia and Europe.
Anyway I don't particularly have a purpose for this, just thought it was interesting to share - because I think the masses on this forum generally advise newbies to completely throw out IGI diamonds as if they're trash when in reality they can represent good value for those of us who are on a tighter budget (ie: almost all of us) and can't afford brand name super-ideals (which is what almost always gets pushed onto folks who come here looking for advicec).
In my research (before buying my IGI diamond), I came across a few interesting studies on IGI vs GIA. Rather than just take the commonly acknowledged view that IGI sucks, I wanted to find objective information. I could only find two studies but they seemed to support the idea that IGI diamond grading is reasonably consistent with GIA standards. I am sure these studies are not news to those of you experts on the forum
https://www.diamonds.net/News/NewsItem.aspx?ArticleID=43417
https://www.diamondscreener.com/edu...ification-labs-gia-vs-igi-grading-and-prices/
The first of these (and the more objective one in terms of methodology) was done by Rapaport in 2013. They sent 10 diamonds of varying sizes and specs to 5 grading labs. Completely anonymously. The results showed the IGI graded the diamonds practically identically to GIA, and both of those were statistically meaningfully more consistent and disciplined in their grading than the 3 labs (AGS was not part of the study). It would be interesting to know which IGI lab they sent the diamonds to, but that is not disclosed unfortunately.
The second study was performed by Diamond Screener (date unknown). They did a retroactive study by combing through James Allen and Blue Nile databases and finding diamonds that were dual-graded by IGI and GIA (n=37). While they work with a larger sample size than Rapaport, this one was less objective because I think all the diamondsThe results support the Rapaport study. In fact, they found they actually found that IGI was generally stricter on color than GIA. They were on par on clarity.
Both studies show IGI diamonds trading between 12-20% less than GIA diamonds despite the data. The results also support what several of the local experts here (Garry H, John Pollard among others) have been suggesting for a long time about IGI being reputable and sometimes even preferred in parts of Asia and Europe.
Anyway I don't particularly have a purpose for this, just thought it was interesting to share - because I think the masses on this forum generally advise newbies to completely throw out IGI diamonds as if they're trash when in reality they can represent good value for those of us who are on a tighter budget (ie: almost all of us) and can't afford brand name super-ideals (which is what almost always gets pushed onto folks who come here looking for advicec).