Diamond Certificates

Diamond certificates

When a client comes into my workshop to view diamonds for their prospective jewellery commission, depending on their requirements, I always try and provide diamond certificates for my larger stones. Sometimes the size of diamond required and budget available means that I will show my client un-certificated diamonds as they are almost always less expensive – a diamond grader has not had to assess the stone and produce the certificate.

Smaller diamonds that I sell, under 0.20cts, generally won’t come with a diamond certificate unless they are of extremely high quality, or a fancy colour.

A diamond that has a certificate does not automatically mean that it is of better quality than an un-certificated diamond. A diamond grader has looked at it and produced a report detailing their opinion of the quality of the diamond.

When I first started in the jewellery industry diamond certificates were generally only issued on diamonds of about half a carat and over. They were used as a way of identifying stones, as well as used as a way of reassuring the purchaser of the quality of the stones. Certificates quickly became used as a tool to sell diamonds, with vendors claiming “my diamonds are better than their diamonds because mine have certificates!”. Certificates soon started to be issued to smaller and smaller diamonds.

One thing to be clear about is that a diamond certificate is not a guarantee of what you are buying. A diamond certificate is a diamond grader’s opinion presented in a written format. I have seen diamonds that on paper seem fabulous, but when you look at them it makes you think that the diamond grader was having a bad day.

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Another thing to be aware of, is that when diamonds are graded for the issue of a certificate they are viewed under specific conditions and using particular tools – conditions that will almost never exist once the diamond is set into a piece of jewellery and worn. The diamonds are clean, they are not set in jewellery, diamonds are viewed under white fluorescent light, and for clarity they are viewed under a magnification of ten. More importantly, a diamond grader knows what to look for and how to use the tools to determine the diamond’s quality.

There are many diamond laboratories offering a range of diamond certificates with different levels of detail. GIA (Gemological Institute of America) diamond certificates are considered to be an industry standard (a lot to do with marketing if you ask me), but this does not mean that diamonds with a GIA certificate are better than diamonds with other certificates. I have compared GIA graded diamonds with other diamonds and sometimes you find that the GIA graded stones are of lesser quality.

Most of my diamonds have GIA certificates. I do sell a few with HRD certificates (Hoge Raad voor Diamant, a Belgian laboratory), and occasionally IGI (International Gemological Institute) certificates. In all cases I check the diamonds to ensure that I agree with the grade that is presented on the certificate. In my opinion a well graded HRD or IGI certificated diamond is preferable to a questionable grade on a GIA certificated stone.

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