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It means that most of the gemological labs don`t give as strict accreditation as jeweler use among themselves.

For this reason, different labs use the same letter grades but with completely different meaning. 

Important to know!

  • Diamond letters grade means nothing without the context of who has done the accreditation.

  • GIA is considered to be the most reliable lab worldwide.

  • No person or company has a patent named over diamond accreditation, therefore anyone can use them as they please.

  • Most of the diamonds sold in the private market are victims to over accreditation.


In order to make it more understandable, let’s use examples.


A diamond is estimated according to a set of characterizing features.


One of those features is it’s color.


The letter “D” represents a completely colorless diamond (clear as water), and as we go up through the ABC up to Z, the letters represent growing yellowish color. This might sound pretty simple, but we must remember that those are human beings that define the color of the diamond and not according to a patented scale which leads to a state in which you can take a diamond to a few different labs and get completely different results:


  • Lab A, the most lenient lab, the diamond will get an “F” color grade.

  • Lab B, less lenient lab, the diamond will get an “H” color grade.

  • Lab C, the reasonable lab, the diamond will get a “J” color grade.

  • Lab D, the strictest lab (the closest to the actual grading of the diamond), the diamond will get a “K”.


The entire range of grading is set to the same diamond!!! We can even see difference of up to 7 grades.


Another example is over accreditation in clarity – more than once we stumble upon a diamond with VS clarity that is actually I2 (and not even a great one). The bottom line is that in our unfortunate experience most customers pay attention only to the printed letters and not to the actual diamond.


So which lab is the strictest?


The strictest and most reliable lab in the diamond market is the American GIA Lab, according to all experts.

Other known strict labs that are IGI and HRD, which are usually 1 grade away from the real GIA grading.


So what is the real meaning of real accreditation?

Diamonds exist before gemological labs and there are consensus about them existing before the accreditation process. It is safe to assume that the gemological labs have been developed mainly to further investigate gemology, and of course to protect customers in the developing diamond market. But even before the gemological labs, there was a diamond trade market and fundamental laws of pricing were developed.


We can assume that the establishment of the America GIA lab in 1931, and the pricing list of Rapaport in 1976, upgraded those fundamental laws to a more organized, detailed and quantifiable in some cases. It is obvious that a trained jeweler with years of experience won’t have to rely on labs to estimate the diamond he is holding, and he is in a serious trouble if he can’t give a reliable estimate of a diamond grading in different labs.


Many times, jewelers buy boxes of not yet accredited diamonds, and must know their market value – just like in any other trade market.


A jeweler with gemological training and knowledge of the market should be able to give accurate grading to a diamond – meaning the grade a diamond will receive under the strictest conditions of the GIA lab.

The problem with private costumers is that a person is asked to trust the grading of the seller although he is new to the jewelry world, which is not a trivial demand.


It is important to emphasize you should be very careful with the purchase of real accredited diamonds, especially in above average purchases that gives an opening for over accreditation or withholding information. Purchase without external accreditation is only by comparison to tester-gems with American accreditation.


So why isn’t everyone buying from GIA?

The issue with GIA is the price. The price of accreditation is extremely high, the accreditation time is very long and therefore very expensive for people who need to keep the market flowing. Beyond the financial unworthiness, of accrediting a small, mediocre stone in high grade lab, there are people who focus on grade letters instead of focusing on the diamond.


The influence of over accreditation on the mind sometimes seems irreversible. People bought a stone with the letter “F” and refuse to comprehend that the actual grade is “K”, in their case the letter “F” stands for a whole other meaning and its not a nice one. Another reason is that many places doesn’t carry GIA accreditation solely because most people are not aware of the subtleties of accreditation and eventually buy temporary accreditation (as long as they look nice)


So how to buy diamonds with non-GIA accreditation

We can estimate the accreditation of other good labs (IGI and HRD) are 1 grade lower than GIA. We should be aware that some temporary labs have a similar name to well known labs in order to fool customers. Treat external accreditation with limited trust and always compare to tester-gems accredited by GIA, before inlay, under florescent light, over colored sheet of paper, with x10 magnification lens.


Don’t be ashamed to buy GIA diamond with a low grade.

In most cases it will be of greater value than other non-GIA accredited diamonds.


Another advantage of GIA is that they specify details such as location and types of inclusion, etc.

While buying diamonds without external accreditation, it is recommended to buy only in places who provide full detailed papers for the diamond, specifying its features, diameter, height and fluorescence.


All singed by a certified gemologist.


Don’t be ashamed to request the full papers for a diamond you are buying.

Don’t be ashamed to ask questions – why the diameter of stone X is shorter the the diameter of stone Y although their weight is the same. What is the color of the inclusions. Or any other question that comes to mind.


Information about DIANOCHE accreditations

GIA – we always hold diamonds with GIA accreditation.


Economic – for customers with limited budget we hold commercial diamond with real accreditation.


Transparency – if a diamond we are selling is relatively cheap, we will give you all the details why.

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