Is there an accepted diamond grading standard?

Rob Bates

A few months back EGL International sent out a release with the following, quite controversial assertion: “At this point in time there is no single, international standard for diamond grading that has national or international status or acceptance.

This didn’t sit well with Martin Rapaport. In his recent editorial on Honest Grading, he writes, “Let us be perfectly clear on this, the GIA is the global diamond grading standard accepted by the international trade and the legal systems of the United States and other countries.”

So who is right? It’s a tricky question.

Technically, you could argue they both are. CIBJO, the international jewelry group, does not endorse any grading scale or procedure, nor do any of the world diamond groups. Hopefully, this recent controversy will lead to some much-needed progress on this front.

Still, at some point the argument becomes a circular one: Labs grade to different standards, so that means there is no standard, which then gives the labs license to grade however they want. As Rapaport says, that will ultimately lead to anarchy. What’s to stop any lab from grading everything a D flawless? Why even have grading labs—or diamond grades—at all?

Whether there is a sole standard as a matter of policy, as a matter of practice, the trade overwhelmingly looks to GIA as the benchmark. Even the labs that deviate most from GIA use the nomenclature it developed, which has very specific definitions (“included,” “flawless,” etc.).

Until we have complete clarity on this point, the answer may be complete transparency. The GIA scale is posted online for the world to see. When we order GIA reports, we assume—and have every right to expect—grading is done to that scale.

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Source JCK Online