Modest Proposal: We Need a New Diamond Grading Scale

With the continued concern about different lab standards, maybe it’s time to look at the bigger picture.

According to Legacy of Leadership, the GIA history written by William George Shuster, the current grading system was developed in the 1950s, in part to bring about a standardized nomenclature for diamond grading. Before the system came about, he writes, “there was widespread ‘soft grading’—that is, careless upgrading—of diamond color by dealers, retailers, and appraisers. Terms such as rarest white, river, or top Wesselton, once reserved only for ‘top color’ diamonds, were used with customers to describe diamonds of somewhat lower quality.” 

Now, it seems, we are in similar position—with the leniant grades coming from labs that use the GIA-developed terminology but don’t always grade to GIA standards.

So what is the solution? The first option is to find a way to prevent labs that deviate from the GIA scale from using the GIA-developed nomenclature. It is not clear how that would be enforced—other than by what we are seeing now: lawsuits.

But maybe we should flip that idea. Perhaps it’s time to invent a whole new diamond grading system. I talked a bit about this on the Four Grainer podcast, and while I doubt this will happen, when I bring it up no one has called me crazy. (Yet.)

The current diamond-grading nomenclature is not proprietary. Everyone uses the GIA color and clarity scales. If GIA—or another industry group—developed a new system it could be legally protected. Of course, if only GIA used it, that might stand in the way of widespread trade adoption. So perhaps the scale could be licensed to different labs, provided those labs grade to the set criteria. (This would fit with GIA’s public-benefit mission.) That would ensure we don’t have a situation like we have now, where the system is so widely used that it becomes abused.

There are other reasons to update the system. It was developed in the 1950s, almost 70 years ago. Technology has taken huge leaps forward since then. It might be possible to develop a scale that is less subjective than the current system, that delivers more repeatable results.

That will likely mean a simplified scale where the differences in grades are more obvious to viewers.  When GIA developed its cut grade, it ran a series of tests to see if observers could notice the difference between, say, a cut graded “excellent” and one ranked “very good.” The final system took that feedback into account.

That would be a great formula to apply to color and clarity. It is often hard for people out of the trade (and even in it) to tell the difference between an “E” and “F” stone; that’s part of the reason for the current problems. If most consumers can’t tell the difference between those grades, if they don’t truly distinguish a stone’s appearance, what real good are they? Let’s develop a system where the grades consistently mean something—to consumers as well as the trade. The new scale might also be more transparent, with the differences between each ranking posted online. 

Now, it’s easy to come up with reasons why this won’t happen. The current system is so much a part of the industry that changing it could cause massive upheaval and chaos. And if traders must get their stones regraded, that could cause more work for the GIA labs—and they are coping with a substantial backlog already.   

Plus, this trade is not great about coping with change. But when people have no choice, they adjust. We all see what happens when, say, Facebook changes its design. Users gripe, and then they all go along with it. And there is a precedent here. When GIA added a cut grade, many predicted upheaval. But in the end, everyone adjusted and survived.

So while this is a long shot, it’s worth having a discussion about. This industry has seen so many changes, and yet it still talks about diamonds using a system developed in the Eisenhower years. It may be time for Diamond Grading Scale Version 2.0.

JCK News Director