Diamond Charts

Preferred Proportions Round Diamonds

  Ideal Proportions Acceptable
Depth Percentage: 60.2% - 62.7% 57.0% - 64.0%
Table Percentage: 53% - 57.0% 53.0% - 64.0%
Polish: Very Good to excellent Good to Very Good
Symmetry: Very Good to excellent Good to Very Good
Girdle: Thin to medium Thin to Thick
Culet: None to very small None to medium

Preferred Proportions for Oval, Pear, Marquise, and Heart Shaped Diamonds

  Ideal Proportions
Depth Percentage: 58.9% - 65.4%
Table Percentage: 53% - 64%
Polish: Good to excellent
Symmetry: Good to excellent
Girdle: Thin to thick

Preferred Proportions for Emerald and Radiant Cut Diamonds

  Ideal Proportions
Depth Percentage: 59.9% - 69.0%
Table Percentage: 59% - 69%
Polish: Good to excellent
Symmetry: Good to excellent
Girdle: Thin to thick

Preferred Proportions for Princess Cut Diamonds

  Ideal Proportions
Depth Percentage: 64.0% - 75.0%
Table Percentage: 59% - 72%
Polish: Good to excellent
Symmetry: Good to excellent
Girdle: Thin to thick

AGA Accredited Gem Appraisers Cut Grading Chart for Round Brilliant Cut Diamonds

  Hearts and Arrows American Ideal Cut International Fine Cut US Domestic Average Cut Below Average Cut
Cut Classes Hearts Arrows Class 1A Class 1B Class 2A Class 2B Class 3A Class 3B Class 4A Class 4B
Table % < 0.49ct < 0.49ct < 0.49ct < 0.49ct All Weight All Weight All Weight All Weight All Weight
53-57% 53-59% 59.1-63% 62.1%-63% 63.1-64% 51-51.4% 64.1-67% 50.5-50.9% 67.1-70% 50-50.4% 70.1-72% 49-49.9% >72% <49%
53-63% are weight specific in 1A, 1B, 2A grades 51.5-51.9% 51.5-51.9%
> 0.50 > 0.50 > 0.50 > 0.50
53-58% 34-34.2% 34.8-35% 60.1-63% 51.5-51.9%
 
Crown Angle ˚ 34.3-24.7˚ 34-34.2˚ 34.8-35˚ 32.1-33.9˚ 35.1-35.8˚ 31.6-32˚ 35-9-36.4˚ 30.1-31.5˚ 36.5-37.9˚ 29.6-30˚ 38-39.4˚ 29-29.5˚ 39.5-40.5˚ <29 <40.5˚
 
Crown Height % < 0.49ct < 0.49ct < 0.49ct < 0.49 All Weight All Weight All Weight All Weight All Weight
14-16.3% 12.8-13.9% or 16.4-16.8% 11.6-12.7% or 16.9-17.9% 11.1-11.5% or 18.0-18.1% 11.1-11.5% or 18.0-18.1% 9.6-11% or 18.2-19.3% 8.5-9.5% or 19.4-20.5% 7.8-8.4 or 20.6-21.8% <7.8% or >21.8%
> 0.50ct > 0.50ct > 0.50ct > 0.50ct
14.3 - 16.3% 13.5-14.2% or 16.4-16.8% 11.6-13.5% or 16.9-17.9%
Pavillion Depth % 42.8 - 43.2% 42.5-42.7 % 43.3-43.5% 42-42.4% 43.6-44% 41.5-41.9% 44.1-44.9% 41-41.4% 45-45.5% 40.5-40.9% 45.6-46% 38-40.4% 46.1-46% <38% >48%
Girdle Thickness % Thin to Med, Med to Slightly Thick 1.7-3% Very Thin to Med, Thin to Slightly Thick 1.5-4.5% Very Thin to Slightly Thick 1-4.5% Very Thin to Thick 1-5.5% Very Thin to Very Thick 0.4-7% Extremely Thin to Extremely Thick 0-7%
Total Depth % 58.7-62.3% 58.7-62.3% 58.3-58.69% 62.31-62.99% 57.9-58.29% 63-63.5% 57.5-57.89% 63.51-63.8% 57-57.59% 63.81-64.1% 58.5-56.99% 64.11-65% 55-56.49% 65.1-67% <55% >67%
Polish / Symmetry Excellent Excellent or Very Good Excellent to Good Good or Fair Poor

AGA Accredited Gem Appraisers Cut Grading Chart for Princess Cut Diamonds

  Ideal Cut Premium Cut International Fine Cut US Domestic Cut Below Average Cut
Cut Classes Class 1A Class 1B Class 2A Class 2B Class 3A Class 3B Class 4A Class 4B
Table % 62 - 68% 60 - 72% 59 - 74% 58 - 78% 56 - 82% 53 - 85% 50 - 88% <50% >88%
Crown Height % 10 - 15% 8.5 - 16% 8 - 16.9% 6 - 19% 5 - 19% 4 - 19.9% 3 - 20.9% <3% >20.9%
Girdle Thickness % Very Thin to Slightly Thick or Thin to Thick 0.4% to 3% or 1% to 5.5% Very Thin to Thick 0.4% to 5.5% Very Thin to Very Thick 0.4 to 7% Very Thin to Very Thick 0.45 to 7% Extremely Thin to Extremely Thick 0% to > 7%
Total Depth % 64 - 75% 58 - 80% 57 - 83% 56 - 84% 83 - 85% <53% >85%
Polish / Symmetry Excellent to Good Good to Fair Fair to Poor

AGA Accredited Gem Appraisers Cut Grading Chart for Radiant and Emerald Cut Diamonds

  Ideal Cut Premium Cut International Fine Cut US Domestic Cut Below Average Cut
Cut Classes Class 1A Class 1B Class 2A Class 2B Class 3A Class 3B Class 4A Class 4B
Table % 60-65.5% 65.6-68% 59-59.9% 68.1-69.5% 58-58.9% 69.6-72% 57-59% 72.1-74% 56-59% 74.1-76% 53-55.9% 76.1-78% 50-52.9% > 78% < 50%
Crown Height % 12.3 - 14.4% 11.9-12.2% 14.5-15% 11.5-11.8% 15.1-15.5% 11.1-11.4% 15.6-16.2% 9.5-11% 16.3-17% 8.5-9.4% 17.1-18.5% 7.8-8.4% 18.6-19.5% <7.8% >19.5%
Girdle Thickness % Very Thin to Slightly Thick or Thin to Thick 0.4% to 4.5% or 1% to 5.5% Very Thin to Thick 0.4 to 7% Very Thin to Very Thick 0.4 to 7% Extremely Thin to Extremely Thick 0% to > 7%
Total Depth % 60 - 65% 65.1-69% 58-59.9% 69.1-74% 57-57.9% 74.1-78% 56-56.9% 78.1-80% 53-55.9% > 80% < 53%
Rectangular Range Length / Width Ratio 1.5 - 1.75 1.49 - 1.06 1.76 - 1.99 > Class 3 < Class 3
Square Range 0.95 - 1.05
Polish / Symmetry Excellent to Good Good to Fair Fair to Poor

AGA Accredited Gem Appraisers Cut Grading Chart for Pear, Marquise, Heart and Oval Diamonds

  Ideal Cut Premium Cut International Fine Cut US Domestic Cut Below Average Cut
Cut Classes Class 1A Class 1B Class 2A Class 2B Class 3A Class 3B Class 4A Class 4B
Table % 55-60% 60.1-61.5% 53-54.9% 61.6-62% 52-59% 62.1-64% 51-51.9% 64.1-67% 50-50.9% 67.1-70% 49-49.9% 70.1-72% 48-48.9% >72% <48%
Crown Height % 13-14.5% 12.5-12.9% 14.6-15% 12-12.4% 15.1-15.6% 11.1-11.9% 15.7-16.5% 9.7-11% 16.6-17.3% 8.7-9.6% 17.4-18.4% 7.8-8.6% 18.5-19.5% <7.8% >19.5%
Girdle Thickness % Very Thin to Slightly Thick or Thin to Thick 0.4% to 4.5% or 1% to 5.5% Very Thin to Thick 0.4% to 5.5% Very Thin to Very Thick 0.4 to 7% Very Thin to Very Thick 0.4 to 7% Extremely Thin to Extremely Thick 0% to > 7%
Total Depth % 59.0-63.0% 63.1-65.4% 58-58.9% 65.5-68.5% 56-57.9% 68.6-71% 46-55.9% 71.1-73% 43-45.9% >73.0% <43.0%
Length / Width Ratio Pear 1.50 - 1.75 Marquise 1.75 -2.25 Heart 0.98 - 1.02 Oval 1.33 - 1.66 Pear 1.26 - 1.99 Marquise 1.51 - 2.49 Heart 1.24 - 0.91 Oval 1.26 - 1.74 > Class 3 < Class 3
Polish / Symmetry Excellent to Good Good to Fair Fair to Poor

Argyle Pink Diamond Chart

Argyle pink diamonds are unique to the point that a dedicated grading system has been developed by Argyle Pink Diamonds. The system grades each stone predominately by colour. For example, as shown on this chart, a 1p is an intense pink, with graduations in colour through to 9p. Colours range from Red to Pink, Purplish Pink, to Pink Rose, Pink Champagne and Violet.
Pink Diamond Charts