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AGA system appraiser
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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.
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Pear
Cut
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Parameter
name
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Meaning
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2A
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2B
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3A
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3B
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4A |
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Table %
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Table diameter
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53 - 62.0
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52.0 - 64.0
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51.0 - 67.0
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50.0 - 70.0
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49.0 - 72.0
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UpHeight_GIA
%
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Crown height
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12.0 - 15.6
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11.1 - 16.5
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9.7 - 17.3
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8.7 - 18.4
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7.8 - 19.5
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FullHeight
%
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Full height
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59.0 - 63.0
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58.0 - 65.4
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56.0 - 68.5
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46.0 - 71.0
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43.0 - 73.0
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GirdleRatio
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Ratio of
max/min diameters
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1.50 - 1.75
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1.50 - 1.75
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1.26 - 1.99
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1.26 - 1.99
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1.00 - 2.25
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UpAngle
°
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Crown angle
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31.6 - 34.4
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31.0 - 36.0
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30.5 - 37.0
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30.0 - 37.5
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29.0 - 38.0
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Pavilion
%
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N/A
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10 - 25
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10 - 25
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10 - 25
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10 - 25
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10 - 25
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GirdleHeight_GIA
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Girdle thickness
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Thin - Thick
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Thin - Thick
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Very thin
- Very thick
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Very thin
- Very thick
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Extremely
thin - Extremely thick
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| *
All that does not fit 4A group is included
in 4B. |
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