Perhaps the 5th ‘C’ when purchasing a diamond is the CERTIFICATE or diamond report. This important document validates the diamond’s characteristics. A diamond certificate from a ‘no name’ laboratory or jewellery shop is not worth the paper it’s written on, insist on quality grading documents. The world’s foremost diamond report and the leaders in diamond research are the inventors of the 4C’s; the GIA (Gemological Institute of America). There are other laboratories that also use the GIA methods and/or have a very good reputation, they are:

GIA Certification GIA (Gemological Institute of America)
mini__ags AGS (American Gemological Society)
mini__hrd HRD (Antwerp World Diamond Centre)
mini__igi IGI (International Gemological Institute)
mini__egl EGL (European Gemological Laboratory)    DG no longer sells EGL certificiated diamonds

The diamond grading laboratories listed above are the largest, probably the strictest and certainly the most well known of the international gemological centres. There are subtle differences in grading techniques but the overall consensus is usually very close between these institutions. Any other diamond report may warrant further analysis of the laboratories processes and ability to grade in a consistent and unbiased manner that represents a true and fair diamond report. Because the diamond certificate reports the characteristics we have discussed above its vital and imperative it comes from a reputable source. A diamond valuation or appraisal is significantly different from a diamond report or certificate and should not be confused.

ALWAYS insist on a diamond certificate from a major laboratory!

Remember that when buying a diamond there are many characteristics that need to be balanced and reviewed in order to buy quality within your budget.

Every certificate from any lab. will carry its own disclaimer, this from an E.G.L certificate is typical:

‘This examination has been carried out using the current gemological procedures of E.G.L.
The report or seal expresses an opinion at the time of inspection of the stone, not a guarantee, valuation or appraisal. No representation or warranties as to accuracy are made. Diamond grading is not a science; It represents only the best professional opinion of this company [the EGL], which chooses its own standards or norms. A+/- 20% error of judgement is scientifically possible. E.G.L. is expressly held harmless by customers including, but without limitation for any claims or actions that may arise out of negligence in connection with preparation of this laboratory report or seal, or actions based upon the customer’s use of the certificate or seal’

DiamondGeezer.com stresses the following poignant points from this:-

  1. Diamond grading is not an exact science
  2. A certificate is not a guarantee, valuation or appraisal – It’s an assurance
  3. A certificate expresses a single opinion at the time of inspection of the stone
  4. One man’s VS is the next man’s Si
  5. Our advice, know where you are and insist on a certificate from the stricter labs and the GIA gets our strongest endorsement