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RAPLAB® Grading Criteria

The 4 C's are part of a well-known grading system for evaluating diamonds by grading the carat weight, color, clarity and cut. RAPLAB® grades diamonds based on the 4 C's and several additional criteria using sophisticated technology to provide you with a more detailed and informative certification.
The 4 C's are part of a well-known grading system for evaluating diamonds by grading the carat weight, color, clarity and cut. RAPLAB® grades diamonds based on the 4 C's and several additional criteria using sophisticated technology to provide you with a more detailed and informative certification.
The 4 C's are part of a well-known grading system for evaluating diamonds by grading the carat weight, color, clarity and cut. RAPLAB® grades diamonds based on the 4 C's and several additional criteria using sophisticated technology to provide you with a more detailed and informative certification.
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Shape

There are nearly 2,000 different diamond shapes, with the round brilliant cut being most common.

Round, Standard, Brilliant Cut
Rectangular, Standard, Step Cut

Diamond Shapes

Today, there are eight traditional brilliant cuts:
  1. Round (RB )
  2. Cushion(CB)
  3. Heart (HB)
  4. Marquise (MR)
  5. Oval (OV)
  6. Pear (PS)
  7. Rectangular
  8. Square (SQ)
There are other shapes as well; the most familiar are:
  1. Emerald (EM)
  2. Radiant (RD)
  3. Princess (PR)
  4. Triangular (TR)