The art of purchasing diamonds has changed dramatically over the past few decades. One thing just about all potential customers now know is the importance of buying a diamond that has been “certified”. Prior to 1953, diamonds were graded by the buyers and sellers, without a strict set of standards by which to compare them. One can only imagine the haggling and wrangling that must have accompanied most sales! These days there are many professional diamond certification options, from small appraisal companies to very large grading laboratories. We will be taking a look at the five most well-known labs in the world, whose grading reports are believed to directly impact diamond pricing.
The certification of diamonds can be a very subjective process. These labs all grade diamonds on the same criteria; cut, carat, color, clarity (the 4 C’s), shape, fluorescence, symmetry and dimensions being some of the more significant categories. However, human subjectivity and opinion play a big part in how a diamond is graded. The assigned grades, especially in color and clarity, can vary from lab to lab. These differences can result in certain labs developing reputations for being soft, easy graders or hard, strict graders. Although the labs can grade slightly differently, it is reassuring to know that each lab tends to stay very consistent to their own internal standards.
The oldest and most recognized diamond certification organization is the Gemological Institute of America’s Gem Trade Laboratory, usually just referred to as GIA. The GIA invented the laboratory grading process for color and clarity and has a reputation for consistent and accurate color and clarity grading. GIA reports lack some of the technical information and features offered by other labs especially in the area of cut quality analysis.
The IGI, or International Gemological Institute, is possibly the largest independent lab, based on the sheer quantity of stones receiving diamond certification. IGI serves mainly the larger chain stores and a high percentage of their reports are therefore done on commercial quality diamonds.
The European Gemological Laboratory was once a dominant global franchise, but has lost some of that power since splitting into EGL Worldwide and EGL USA. Both branches still have a significant presence in the diamond world, but different practices and standards between their labs has lead to inconsistent grading. EGL reports are considered in the trade to be a grade or two “soft” and are consequently traded at lower prices.
Another very large laboratory and trading center, HRD, is based in Antwerp, Belgium. This lab is dedicated to “Antwerp diamond heritage”. Not surprisingly, HRD reports are particularly well respected Throughout Europe.
One of the smaller new labs is the American Gemological Society laboratory, or AGSL. Some have considered the AGSL more of a “niche” lab, due to their concentration on cut quality during the certification of diamonds. By most accounts, AGSL does the most comprehensive and critical diamond cut quality analysis of any lab in the world. And as the importance of cut quality to the light performance of diamonds has become better understood by the public, the stature of the AGSL has grown considerably. The AGS certificate has become more valued than either GIA or HRD among customers focused on ideal cut diamonds and light performance.
Diamond grading reports have become a critical tool for prospective buyers. Learning the strengths and weaknesses of the different grading labs can help the buyer determine which grading reports are most valuable to them, and can also affect the possible resale price of their diamond in the future. All in all, the diamond grading report is essential to a buyer making an educated and informed purchase.