A diamond certificate or grading report provides an expert opinion on the quality of the diamond and is provided by an independent gemology lab. Trained gemologists with specialized equipment measure the weight and dimensions of the diamond and assess quality characteristics such as cut, color, and clarity.
When purchasing a certified diamond , it is important to note that the grading standards of the various laboratories vary. This variation results in a discrepancy in the quality of diamonds graded in different laboratories, even when they are graded the same color, clarity, or cut. Of the five laboratories that certify the loose diamonds we offer at Brilliance, the Gemological Institute of America (GIA) and the European Gemological Laboratory (EGL) are by far the most popular. When deciding which certification to go with, it is important to understand the vital differences between the grading techniques of the two laboratories.
Comparing the standards of certification of GIA and EGL
Loose diamonds GIA certified are graded using strict standards that are consistent among the various GIA locations. Each GIA diamond is carefully evaluated by at least four expert gemologists who are chosen at random to guarantee an unbiased evaluation. The EGL’s grading standards are more lenient and vary among the EGL locations, with EGL USA locations generally grading on a slightly stricter scale than its International counterpart. As a general rule, an EGL certified diamond will compare equally in quality to a GIA certified diamond that is graded two color grades and one clarity grade lower. For example, an EGL diamond graded G in color and VS2 in clarity is comparable to a GIA diamond graded I in color and SI1 in clarity. As a result, GIA certified diamonds are considered more valuable and provide the consumer with more confidence in the product they are purchasing.
However, there is a benefit to choosing an EGL certified diamond. Due to the discrepancy in the grading standards used, an EGL diamond graded the same color and clarity as a GIA diamond will be less expensive. This is seen as an advantage to those who consider the ratings stated on the certificate a priority when choosing