Diamond proportions | Original-Diamonds
Hearts & Arrows Ideal Cut corresponds to Hearts & Arrows
Displays the visual phenomenon that appears in the Worlds finest Ideal round brilliant cut diamonds. A Hearts & Arrows Ideal Cut Diamond is the ultimate, supreme most magnificent cut diamond man can produce; it accounts for less than 1 % of all diamonds cut. . The highest grades of polish and symmetry allow it to reflect more light than the standard American ideal cut.
The phenomenon of the Hearts & Arrows Ideal Cut may be view easily by any body that possesses a proportion or fire scope. Top 1%
American Ideal Cut corresponds to Superb Ideal Cut
Corresponds to approximately 16% of the top diamond quality based on cut. The range for the proportions as defined by the American Gem society: Table Diameter: 52.4% to 57.5%, Crown Angle: 33.7 degrees to 35.8 degrees, Girdle Thickness: Thin to Slightly Thick (.51% to 2.95%), Pavilion depth percentage: 42.2 % to 43.8%, Culet: (Pointed) None, Very small to Medium, Total Depth: 58.7% to 62.3%.Noting good symmetry and polish. These percentage ranges justify the beauty and quality of the diamond. An Ideal American cut will reflect nearly all light and is truly a top quality, striking and highly prized cut.
International Fine Trade Cut corresponds to Super Fine Cut
Corresponds to approximately 24% of the top diamond quality based on cut. The proportions for International Fine Cut as defined by AGA Accredited Gem Appraisers are set out in the AGA table below. International Fine Trade cut or "Fine Cut "is still with in the range of a well cut diamond, it will reflect most light that enters it and has a healthy beauty. The benefit here starts to become noticeable with price.
American Average Cut or Average Cut corresponds to Classic Cut
Corresponds to approximately 38% of the usual diamond quality based on cut. The proportions for Average Cut as defined by AGA Accredited Gem Appraisers are set out in the AGA table below. Average cut diamonds are more usual commercial cut trade heavily in the bulk of mass produced jewelry .These diamonds are usually cut for weight .An Average cut diamond will reflect light and is sparkly.
Below Average Cut corresponds to Below Average Cut
Corresponds to all the rest of round brilliant shaped diamonds that fall out side normal specific cutting ranges. The proportions for Average Cut as defined by AGA Accredited Gem Appraisers are set out in the AGA table below. These diamonds are too deep, narrow, shallow or wide and lose most of their brilliance and Fire, the light passes through and leaks out the stone. Some of these stone may have an interest and beauty factor, price should be well below superior diamonds.
AGA Accredited Gem Appraisers Cut Grading Chart for Round Brilliant Cut
| Hearts & Arrows Ideal Cut | American Ideal Cut | International Fine Trade Cut | US domestic Average Cut | Below Average Cut | |||||
| Cut classes | Phenomenon | Class 1A | Class 1B | Class 2A | Class 2B | Class 3A | Class 3B | Class 4A | Class 4B |
| Table, % 53%-63% are weght specific in 1A, 1B, 2A grades |
<=.49ct |
<=.49ct | <=.49ct | <=.49ct | all weights | all weights | all weights | all weights | all weights |
| 53-57.5 |
53-59 | 59.1-62 52.9-52 |
62.1-63 51.9-51.5 |
63.1-64 51.4-51 |
64.1-67 50.9-50.5 |
67.1-70 50.4-50 |
70.1-72 49.9-49 |
>72 <49 |
|
| >=.50ct |
>=.50ct | >=.50ct | >=.50ct | ||||||
| 53-58 |
53-58 | 58.1-60 52.9-52 |
60.1-63 51.9-51.5 |
||||||
| Crown angle, ° | 34.3-34.7 |
34.3-34.7 | 34-34.2 34.8-35 |
32.1-33.9 35.1-35.8 |
31.6-32 35.9-36.4 |
31.5-30.1 36.5-37.9 |
29.6-30 38-39.4 |
29-29.5 39.5-40.5 |
<29 >40.5 |
| Crown height, % | <=.49ct |
<=.49ct | <=.49ct | <=.49ct | all weights | all weights | all weights | all weights | all weights |
| 14-16.3 |
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 |
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 |
|
| >=.50ct |
>=.50ct | >=.50ct | >=.50ct | ||||||
| 14.3-16.3 |
14.3-16.3 | 13.5-14.2 or 16.4-16.8 |
11.6-13.4 or 16.9-17.9 |
||||||
| Pavilion Depth, % | 42.8-43.2 |
42.8-43.2 | 42.5-42.7 43.3-43.5 |
42-42.4 43.6-44 |
41.5-49 44.1-44.9 |
41-41.4 45-45.5 |
40.5-40.9 45.6-46 |
38-40.4 46.1-48 |
<38 >48 |
| Girdle Thikness, % Word description and percentages |
Thin, Medium, Slightly thick 1.7-3 |
Slightly thin to slightly thick 1.5-4.5 |
Thin to slightly thick 1-4.5 |
Thin to thick 1-5.5 |
Very thin to very thick 0.4-7 |
Extra thin to extra thick 0-7 |
|||
| Total Depth, % Determined by factors already considered above |
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 |
57-57.46 63.81-64.1 |
56.5-56.99 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 | ||||
Princess Diamond Proportions Cut Chart
| Ideal Cut | Premium Cut | International Fine Trade Cut | US domestic Average 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 |
68.1-71 61.9-60 |
71.1-72 59.9-59.0 |
72.1-77.0 58.9-58 |
77.1-82.0 57.9-56.0 |
82.1-85.0 55.9-53.0 |
85.1-88.0 52.9-50.0 |
> 88.0 < 50.0 |
| Crown height, % | 9-10 |
8.9-8.5 10.1-11 |
8.4-8.0 11.1-11.5 |
7.9-6.0 11.6-13.0 |
5.9-5.0 13.1-15.0 |
4.9-4.0 15.1-17.5 |
3.9-3.1 17.6-18.5 |
<3 >18.5 |
| Girdle Thikness, % Word description and percentages |
Thin to Medium or Medium to Thick 1% to 3.0% or 1.7% to 5.5% |
Thin to Thick 1% to 5.5% > more variance | Very thin to Very thick 0.4% to 7.0% | Extremely thin to Extremely thick 0% to > 7.0% | ||||
| Total Depth, % Determined by factors already considered above |
64-75 |
75.1-80.0 63.9-58.0 |
80.1-83.0 57.9-57.0 |
83.1-84.0 56.9-56.0 |
84.1-85.0 55.9-53.0 |
>85 <53 |
||
| Polish/Symmetry | Excellent to Good | Good or Fair | Poor | |||||
| Square range Length/Width ratios (Preferences only) |
0.95-1.05 |
|||||||
| Rectangular range Length/Width ratios (Preferences only) |
1.5-1.75 |
1.49-1.06 1.76-1.99 |
> Class 3 < Class 3 |
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Pear, Heart, Oval, Marquise Diamond Proportions Chart
| Ideal Cut | Premium Cut | International Fine Trade Cut | US domestic Average Cut | Below Average Cut | ||||
| Cut classes | Class 1A | Class 1B | Class 2A | Class 2B | Class 3A | Class 3B | Class 4A | Class 4B |
| Table, % | 57-60 |
60.1-61.5 56.9-54 |
61.6-62 53.9-53 |
62.1-64.0 52.9-52 |
64.1-67.0 51.9-51.0 |
67.1-70.0 50.9-50 |
70.1-72.0 49.9-49 |
>72.0 <49.0 |
| Crown height, % | 13-14.5 |
12.9-12.5 14.6-15 |
12.4-12 15.1-15.6 |
11.9-11.1 15.7-16.5 |
11.0-9.7 16.6-17.3 |
9.6-8.7 17.4-18.4 |
8.6-7.8 18.5-19.5 |
< 7.8 > 19.5 |
| Girdle Thikness, % Word description and percentages |
Thin to Medium or Medium to Thick 1% to 3.0% or 1.7% to 5.5% |
Thin to Thick 1% to 5.5% > more variance allowed | Very thin to Very thick 0.4% to 7.0% | Extremely thin to Extremely thick 0% to > 7.0% | ||||
| Total Depth, % Determined by factors already considered above |
59.0-63.0 |
63.1-65.4 58.9-58.0 |
65.5-68.5 57.9-56.0 |
68.6-71.0 55.9-46.0 |
71.1-73.0 45.9-43.0 |
> 73.0 < 43.0 |
||
| Length/Width ratio Trade Preferences. A matter of personal taste and choice. |
Pear 1.50-1.75 Marquise 1.75-2.25 Heart 0.98-1.02 Oval 1.33-1.66 |
1.26-1.99 1.51-2.49 1.24-0.91 1.26-1.74 |
> Class 3 < Class 3 |
|||||
| Polish/Symmetry Not a primary determining factor |
Excellent to Good |
Good or Fair | Poor | |||||
Emerald & Radiant Diamond Proportions Chart
| Ideal Cut | Premium Cut | International Fine Trade Cut | US domestic Average Cut | Below Average Cut | ||||
| Cut classes | Class 1A | Class 1B | Class 2A | Class 2B | Class 3A | Class 3B | Class 4A | Class 4B |
| Table, % | 61-63.5 |
63.6-64.1 60.9-60 |
64.2-65.0 59.9-59.0 |
65.1-69.0 58.9-58 |
69.1-74.0 57.9-56.0 |
74.1-76.0 55.9-53.0 |
76.1-78.0 52.9-50.0 |
> 78.0 < 50.0 |
| Crown height, % | 12.3-14.4 |
12.2-11.9 14.5-15 |
11.8-11.5 15.1-15.5 |
11.4-11.1 15.6-16.2 |
11.0-9.5 16.3-17.0 |
9.4-8.5 17.1-18.5 |
8.4-7.8 18.6-19.5 |
< 7.8% > 19.5 |
| Girdle Thikness, % Word description and percentages |
Thin to Medium or Medium to Thick 1% to 3.0% or 1.7% to 5.5% |
Thin to Thick 1% to 5.5% > more variance | Very thin to Very thick 0.4% to 7.0% | Extremely thin to Extremely thick 0% to > 7.0% | ||||
| Total Depth, % Determined by factors already considered above |
60-65 |
65.1-69.0 59.9-58.0 |
69.1-74.0 57.9-57.0 |
74.1-78.0 56.9-56.0 |
78.1-80.0 55.9-53.0 |
> 80.0% < 53.0% |
||
| Polish/Symmetry Not a primary determining factor |
Excellent to Good |
Good or Fair | Poor | |||||
| Square range Length/Width ratios (Preferences only) |
0.95-1.05 |
|||||||
| Rectangular range Length/Width ratios (Preferences only) |
1.5-1.75 |
1.49-1.26 1.76-1.99 |
> Class 3 < Class 3 |
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Information courtesy of D.S. Atlas, Accredited Gem Appraisers, © AGA 1998-2002
Marcel Tolkowsky
Marcel Tolkowsky was a Belgium diamond cutter, In 1919 he publicized his determinations for the most attractive and balanced cut for round brilliant diamonds, his proportions where based on experience, maximum beauty, collected opinion and mathematical calculation, this set the industry standard for many years, Marcel could be described as the father of the Modern Brilliant cut.
His proportions for cutting were followed and approximated for many years.
Diamonds are some times improperly called Tolkowsky cuts when their proportions range only approximates that of the exact proportions determined by Tolkowsky.
These proportions are
Now with increased desire for perfection and with greater beauty the Hearts and Arrows Ideal Cut Diamond was created too even more exacting proportions of balance and beauty , remembering that only an exact small changeable ratio of proportions creates this Phenomenon of the Hearts and Arrows effect.
The American Gem Society or AGS has laid down their determination Ranges for Ideal Brilliant Cut Diamonds. The Tables are as follows:
AGS Proportions Charts for Brilliant Cut
| Average Pavilion Depth, % | AGS Grade | Average Table Diameter, % | AGS Grade | Crown Angle in degrees | AGS Grade |
| 39,4 and less | 10 | 46.3 and smaller | 10 | 28.3 and less | 10 |
| 39.5-40.1 | 9 | 46.4-47.3 | 9 | 28.4-29.1 | 9 |
| 40.2-40.6 | 8 | 47.4-48.3 | 8 | 29.2-29.6 | 8 |
| 40.7-41.1 | 7 | 48.4-49.3 | 7 | 29.7-30.1 | 7 |
| 41.2-41.6 | 5 | 49.4-50.3 | 7 | 30.2-30.6 | 6 |
| 41.7-42.1 | 3 | 50.4-51.3 | 3 | 30.7-31.1 | 5 |
| 42.2-43.8 | 1 |
51.4-52.3 | 1 |
31.2-31.6 | 4 |
| 43.9-44.3 | 0 |
52.4-57.5 | 0 |
31.7-32.1 | 3 |
| 44.4-44.8 | 1 |
57.6-59.5 | 1 |
32.2-32.6 | 2 |
| 44.9-45.3 | 3 | 59.6-62.0 | 2 |
32.7-33.6 | 1 |
| 45.4-45.8 | 4 | 62.1-63.5 | 3 | 33.7-35.8 | 0 |
| 45.9-46.3 | 5 | 63.6-65.5 | 4 | 35.9-36.3 | 1 |
| 46.4-46.8 | 7 | 65.6-67.5 | 5 | 36.4-36.8 | 2 |
| 46.9-47.5 | 8 | 67.6-69.5 | 6 | 36.9-37.3 | 3 |
| 47.6-48.5 | 9 | 69.6-71.5 | 7 | 37.4-37.8 | 4 |
| 48.6+ | 10 | 71.6-73.5 | 8 | 37.9-38.3 | 5 |
| 73.6-75.5 | 9 | 38.4-38.8 | 6 | ||
| 75.6+ | 10 | 38.9-39.3 | 7 | ||
| 10 | 39.4-39.8 | 8 | |||
| 10 | 39.9 and greater | 9, 10 |
| Polish and Symmetry Characteristics | AGS Grade | Girdle Thikness | AGS Grade | Culet Size | AGS Grade |
| Extremely Difficult 10x | 0 |
Extremely Thin | 3 | None, Very small | 0 |
| Very Difficult 10x | 1 |
Very Thin | 1 |
Small, Medium, Slightly Large | 1 |
| Difficult 10x | 2 |
Thin, Medium | 0 |
Large | 3 |
| Easy 10x | 3 | Slightly Thick, Thick | 2 |
Very Large | 5 |
| Very Easy 10x | 4 | Very Thick | 5 | Extremely Large | 7-10 |
| Obvious 10x | 5 | Extremely Thick | 7-10 | ||
| Unaided Eye | 6 | ||||
| Easy Unaided Eye | 7, 8 | ||||
| Obvious Unaided Eye | 9, 10 |
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