Diamond graders draw a diagram of the inclusions on what is known as the diamond grading plot. Learn about diamond clarity at AmericanGemSociety.org.
The Diamond Grading Plot
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Diamond graders draw a diagram of the inclusions in the diamond (left) to a diagram (right) to create a map of the diamond's inclusions, called the "plot”. The plot will be used to help the diamond lab give the diamond its final grade on the clarity scale.

 Diamond Grading Plot

A stone plot on a diamond grading report is a bit like a fingerprint. It records the significant internal and external characteristics of the diamond as a way to help positively identify that diamond and justify its clarity grade. Every diamond is unique!


Translation plane

 Transition Plane

Figure 4.  This is how plots are traditionally oriented.  Note that the feather in bezel #1 also breaks through the girdle to the upper half on the left #1 lower half.

Rotation Plane

Learn more about diamond buying, or find an AGS Jeweler in your area.


Mission Statement

The American Gem Society (AGS) is a nonprofit trade association of fine jewelry professionals dedicated to setting, maintaining and promoting the highest standards of ethical conduct and professional behavior through education, accreditation, recertification of its membership, gemological standards, and gemological research.

The Society is committed to providing educational products to inform and protect the consumer and to contributing to the betterment of the trade by creating industry standards to protect the jewelry-buying public and the fine jewelry industry as a whole.

AGS Laboratories, founded to support the AGS mission, is a nonprofit diamond grading laboratory with a mission of consumer protection. Adhering to the AGS Diamond Grading Standards, AGS Laboratories is dedicated to offering diamond grading reports that provide consistency and accuracy based on science.

American Gem Society