This document shows what criteria DiamCalc uses for diamond grading according to AGA system
The data listed here is not an official AGA data. It is provided
here for possibility to check its suitability for your purposes.
OctoNus software recommends that you check the data and modify
it as necessary as described here
before using DiamCalc to grade diamonds for commercial purposes.
Heart Cut |
Parameter name |
Meaning |
2A |
2B |
3A |
3B |
4A |
Table % |
Table diameter |
53.0 -62.0 |
52.0 - 64.0 |
51.0 - 67.0 |
50.0 - 70.0 |
49.0 - 72.0 |
UpHeight_GIA % |
Crown height |
12.0 - 15.6 |
11.1 - 16.5 |
9.7 - 17.3 |
8.7 - 18.4 |
7.8 - 19.5 |
FullHeight % |
Full height |
59.0 - 63.0 |
58.0 - 65.4 |
56.0 - 68.5 |
46.0 - 71.0 |
43.0 - 73.0 |
GirdleRatio |
Ratio of max/min diameters |
0.98 - 1.02 |
0.98 - 1.02 |
0.91 - 1.24 |
0.91 - 1.24 |
0.80 - 1.50 |
UpAngle ° |
Crown angle |
31.6 - 34.4 |
31.0 - 36.0 |
30.5 - 37.0 |
30.0 - 37.5 |
29.0 - 38.0 |
Pavilion % |
N/A |
10 - 25 |
10 - 25 |
10 - 25 |
10 - 25 |
10 - 25 |
GirdleHeight_GIA |
Girdle thickness |
Thin - Thick |
Thin - Thick |
Very thin - Very thick |
Very thin - Very thick |
Extremely thin - Extremely thick |
* All that does not fit 4A group is included in 4B. |
AGA appraiser tables and translation tables:
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