Why are IGI diamonds less expensive?

[Blink]

Hi! So I'm on a diamond hunt right now and I see that IGI diamonds are a lot less than AGS or GIA. I was under the impression that it was because they over graded, so I did some googling and found this article

http://www.diamonds.net/News/NewsItem.aspx?ArticleID=43417

This says that out of 10 diamonds, 9/10 times IGI gave the exact same grade as GIA except for a one grade difference in color.

Is this not accurate? I think I saw somewhere that IGI isn't as strict on cut, but as long as I'm looking at RB's and I run the numbers through the HCA, shouldn't that be fine? Maybe there are more studies out there that I didn't find, but I would love to read more about it if there are!

Thank you so much everyone!

 

[John P]

Some of this depends on the report format you're considering. The article you linked refers to "loose diamond" grading reports.

The negative sentiment in the USA is connected to IGI New York's "finished jewelry appraisal-reports." These reports may have split-grades and they include an arguably (much) inflated replacement-value printed on the document; historically misused by salespeople to point at what a "bargain" a piece is. IGI New York is the only IGI location to issue those reports, by the way.

In the global picture IGI enjoys the strong reputation reported in the Rapaport article. Their loose diamond grading is seen as reliable and consistent. The "Hearts & Arrows" grading report issued by IGI Hong Kong enforces a stricter cut standard and has a reputation in China similar to the reputation of AGSL's Platinum Report here in the USA.

 

[Rockdiamond]

HI Blink,
I have also found that IGI is reasonably accurate
Regardless, in the US - and other English speaking countries where diamonds are popular ( UK,Canada and Australia/NZ) GIA's reputation has precluded any other lab from "breaking in"
In other words, in a case where a cutter or dealers offers the exact same diamond- one case with a GIA report, versus an IGI report, the GIA stone will command a premium.
Why?
I'm sure IGI would like to find out- but that's the current state of affairs in US based trading.
John does a lot of work in the far east, and the situation there may be different.

 

[Sunstorm]

Nowadays IGI is considered as quite accurate, reliable and consistent in Europe. GIA is a name, which is what you pay for. I cannot speak for the US IGI reports but it has been stated that they are not at the level of those produced in Europe. I think that for high value stones GIA is still the way to go, or AGS in the US but otherwise IGI outside the US is perfectly fine.