You may well already know that a diamond is graded according to its four C’s – those of carat, color, clarity and cut. But perhaps less generally well-know is how the grading is carried out and by whom. Diamonds are not formally appraised by jewelers, but by a team of qualified gemologists.
A diamond certificate is also known as a diamond quality document, a diamond dossier, or a diamond grading report. It is produced by gemologists, who evaluate and measure the gemstones – with their expert eyes – and a microscope. An analysis of the diamond’s clarity, color, dimensions, polish and symmetry is undertaken, along with several other characteristics, in order to produce the validated certificate. Three to six (sometimes more) individual gemologists will look at the diamond in order to assess its grade so as to be sure that the report is as accurate and unbiased as possible.
Two Main Authorities for Grading
There are two main types of certificate, the AGSL and the GIA. The GIA certificate is produced by a team from the Gemological Institute of America, and the AGSL report is produced by the American Gem Society Laboratories – both highly esteemed organizations. Both certificates are respected and viewed as consistent and accurate, however there are a few minor differences between the two.
The GIA Certification
The two main reports produced by the GIA are
- The full issued GIA document, which give the diamond’s properties in full, as well as plotting the clarity characteristics of the stone. This comprehensive report is usually only carried out on stones of over 1 ct.
- The other GIA compiled dossier provides the full individual properties of the stone, but, instead of showing the clarity plotting details, creates a laser inscription registry number on the girdle of the diamond. This is generally used on smaller diamonds to save time and money.
The AGSL Certification
The AGSL reports are mostly carried out on the highest quality of diamonds – those which are ideal cut round diamonds. Diamonds of this standard have generally met the criteria of what is considered perfect in terms of proportion, polish and symmetry.
Why is a Diamond Certificate Important?
Nowadays there are a multitude of ways to artificially treat and enhance the color and clarity of diamonds, and even dealers and retailers cannot detect whether a diamond has been altered. Only the advanced equipment of gemologists can uncover these sophisticated alterations, which often take the form of filling in the cracks in diamonds – making an otherwise worthless diamond look perfect and complete. Certification the only sure way of making sure a diamond is authentic.
A certificate is also essential if you later decide to sell the diamond if you are to get a fair market price for it, and may even add value, since the prospective buyer will not have to pay for his or her own appraisal. It can also speed up the selling process since buyers are more likely to be attracted to certificated diamonds.
Where can I buy a Certificated Diamond?
Almost all good jewelers sell certified diamonds, the most reputable only selling diamonds which have certificates. There are some diamonds, however for which certificates are hard to come by. These include diamonds which are priced at under $1000, diamonds whose weight is less than 0.5 ct and diamonds whose clarity and color is lower than S12 and I.
A diamond certificate will help give you confidence when purchasing a diamond. And, when buying a certified diamond, it’s important to check that the diamond matches its certificate.