When purchasing a diamond, always make sure it comes from a trusted source.
A diamond certificate — also called a diamond grading report, a diamond dossier, or a diamond quality document — evaluates a diamond on various components but before making any diamond purchase, it's essential to know that the grading standards of the various laboratories. Diamonds can be certified on the same color, clarity and cut, but receive different gradings from different laboratories.
When it comes to certifying and buying diamonds, the Gemological Institute of America (GIA) and the European Gemological Laboratory (EGL) are among the most popular and well-known laboratories. Customers have to decide which certification to go with, and so it's important to understand the differences between the grading techniques of the two laboratories.
The GIA was established in 1931 by Robert M. Shipley and is considered worldwide as the leading authority in gemology. GIA patented the first gemological microscope in 1937, enabling gemologists to examine the interior of gems. Their staff of 1,400 employees includes scientists, certified diamond graders, researchers and educators. The GIA established the first globally accepted standard for describing diamonds — the “4Cs” (cut, clarity, color, carat weight) — and the International Diamond Grading System which, to this day, is the worldwide standard for evaluating diamond quality.
Founded in Europe in 1974, EGL employs over 1,100 scientists, diamond graders and educators. The EGL was the first to grade diamonds less than one carat in weight and is also known for introducing the “SI3” grade to the diamond standard.
GIA uses stricter standards than EGL when it comes to grading and certifying diamonds, and is more uniform in its grading. For that reason, GIA certified diamonds are considered more valuable. Each GIA diamond is evaluated by a team of expert gemologists who are chosen at random to guarantee an unbiased evaluation. Also, diamonds are analyzed under complete client anonymity to ensure objective analysis. As a non-profit organization, GIA operates independently of commercial and private interests, political lobbies and advocacy groups.
GIA explains the step-by-step process of how it grades diamonds on its website.
The EGL’s grading standards are more lenient and vary among the EGL locations. The general rule is that an EGL certified diamond will compare equally in quality to a GIA certified diamond that is graded two color grades and one or two clarity grades lower, but there are some exceptions. EGL certified diamonds of the same grading also sell for less than GIA certified diamonds.
The upside is that an EGL diamond graded the same color and clarity as a GIA diamond will be less expensive. Unlike the GIA, the EGL is a for-profit organization, making it susceptible to outside influences. EGL provides on its website an overview of what is included in its diamond report.
Most of the diamonds carried by Allurez are certified by GIA or the American Gem Society Laboratories (AGSL), but also offered are diamonds certified by EGL and the International Gemological Institute (IGI). Certification is included with most loose diamonds and diamond jewelry purchased from the "design your own engagement ring" section of Allurez.com.