Honest Grading

“Overgrading is not just a legal issue, it is an ethical issue facing the diamond and retail industry.”
Article facts: Martin Rapaport (CEO, Rapaport Group)

“Is it okay to sell a diamond as a G color when the color is really an N? How about if the G is really an L? Shockingly, a lot of the people in the diamond trade think that it’s perfectly okay to use third-party diamond grading reports to overstate the colour and clarity of the diamonds they sell. Diamond grading reports labeled EGL International (EGLI) commonly use Gemological Institute of America (GIA) terminology to describe diamonds as four or more colour/clarity combination grades higher than what the GIA would give the same stones. Overgrading has become institutionalised. Hundreds of thousands of diamonds worth billions of dollars have been sold to consumers with overgraded reports in the past few years.”

Definition: Overgraded Diamond
An overgraded diamond is a diamond graded using GIA terminology that when verified by the GIA is more than one color or one clarity lower than the original grade.

For this reason John Macintyre & Son soley sell certificated diamonds graded by GIA to put it simple…they are the best!



The GIA is the global diamond grading standard accepted by the international trade and the legal systems of the United States and other countries.


The systematic grading of a diamond by multiple gemologists yields diamond grading results that are almost always consistent within a one color or one clarity range. At the very most, in rare, exceptional circumstances, there might be an error with a gemological difference of two colors or two clarities. In any case, when using GIA standards, there is no justification for the consistent overgrading of diamonds by more than one color or clarity grade.


Some suppliers think that it is okay to misrepresent quality as long as the price is low. They further maintain that the consumer somehow knows that the quality is overstated because the price is so low. In fact, there is no ethical or legal justification for such misrepresentation. Consumers are incentivized to buy because they think they are getting a “good deal” when in fact they are not getting as “good a deal” as they think because the quality has been exaggerated more than they realise.


The foundation of the diamond business is based on the honesty and integrity of diamond traders. The oldest rule in the business is that sellers have to stand behind the products they sell.