Understanding Diamond Cut Grades

Understanding Diamond Cut Grades

When you’re in the market for a diamond, it’s easy to get overwhelmed by the plethora of options and gradings you’re presented with. From choosing which cut is right for you to ensuring you purchase the best quality diamond for your budget, diamond buying has a lot of things to consider. Understanding the various diamond cut grades can make the process much smoother and more manageable.

Diamond Cut Grades

It’s widely known that the cut of a diamond is critical to determining its specific fire and brightness, but did you know this can be (and is) graded by professionals? Essentially, each diamond is graded by experts in the field and given a “report card” of sorts, showing how each gem measures up to standards.

It is these grades that assures the consumer they are investing in the absolute highest quality diamond they can afford. Understanding these grades is the key to making the most educated decisions when it comes time for your purchase.

Who Grades Them?

There are several different organizations throughout the world that offer diamond grading services. Among them, two are widely accepted as the most respected reputations in the United States:

  • The Gemological Institute of America (GIA)
  • The American Gemological Society (AGS)

Understanding the Grading Systems

Since the grading systems for diamonds aren’t judged by a universal method, it’s important to understand how each organization determines their grades. While the GIA and the AGS each use sequential grading systems, their scoring methods are quite different.

According to the respective websites, the GIA and the AGS use different grading scales when determining the overall quality of a diamond. GIA uses a word scale that grades each piece from its top ranking “Excellent” grade on down to its lowest ranking “Poor” grade.

By contrast, AGS uses a numerical scale to grade diamond cuts. These vary from the coveted ideal grade of “0” to the poorest grade of “10.”

The GIA Standard

Under the GIA standard, diamond cuts are graded on a 5-grade scale and includes only those diamonds in the round brilliant cut with higher color ranges. This scale includes the following sequential grades, self-explanatory by their grade names:

  • Excellent – highest grade possible
  • Very Good – slightly greater dark portions than an excellent grade
  • Good – a nice diamond, but with limited shine and scintillation
  • Fair – lower quality diamonds, usually with shallow cuts that limit light refraction
  • Poor – the lowest grade possible for diamond cuts

The AGS Standard

While similar in using a sequential grading system, the AGS standard of grading varies significantly from the GIA method. In order to understand the AGS standard, keep in mind one simple fact: the lower the number, the greater the quality of diamond cut.

AGS uses a scale of 0-10 to grade diamond cuts and the other Cs (clarity and color) as well. In terms of understanding diamond cut grades, their scale correlates as follows:

  • Score 0 – the highest grade possible, or “ideal” cut
  • Score 1 – this score is an excellent quality cut, with only slight variations of dark
  • Score 2 – equivalent to a “very good” score from GIA
  • Score 3-4 – equates to a “good” score with some dulling of scintillation
  • Score 5-7 – this is the “fair” range with moderate shine and fire
  • Score 8-10 – these are the lowest scores, translating to a “poor” grade

Different jewelers utilize grading scores from different organizations but understanding the basics of each can help in your selection process. No matter which method is used, as long as you are educated on their scales, you can be sure you’re getting the best quality diamond for your budget.