Total Depth Percentage
The Total Depth Percentage is a very important element of a diamonds proportions and is greatly responsible for the amount of brilliance that a diamond will display. The ideal specifications for total depth percentage vary depending on the shape of the diamond you choose.
To learn Ideal Depth Percentage for the following diamond shapes, click the diamond shape you are interested in from the list below. The same basic principles explained below regarding Total Depth Percentage of a Round Brilliant Cut diamond also apply to other diamond shapes.
Click Diamond Shape To Ideal Depth Percentage
Round Brilliant Cut Depth Percentage:
To provide greater clarity read the following to learn how Total Depth Percentage affects a Round Brilliant Cut Diamond. The facets on the bottom of a round brilliant cut diamond are called pavilion facets. When you look at a round brilliant cut diamond face-up, the pavilion facets act as mirrors which reflect the image of the table, the large facet on the top of the diamond. This white table reflection seen within the center of the diamond provides the sparkle in the center of the diamond.
Round brilliant ideal cut diamonds exhibit a white table reflection that appears in the center of the table. This reflection should be 1/4 to 1/2 the size of the large table facet on top of the diamond.
Total Depth Percentage = Depth Measurement / Average Diameter
Example: 60% = 6 millimeters / 10 millimeters = .60
Ideal to Very Fine Cut Diamonds have total depth percentages between 59% and 63%. Diamonds within this range usually provide excellent brilliance. Diamonds that have depths outside these ranges usually cost less, but a degree of brilliance is lost. The diagram below illustrates how the white table reflection changes in size as the depth percentage changes.
The white table reflection appears larger as the total depth percentage increases and smaller as depth percentage decreases.
- 55.0% = Girdle seen in table
- 56.0% = reflection broken up
- 57.0% = reflection broken up
- 58.0% = 1/8 size of table
- 59.0% = 1/4 size of table
- 60.0% = 1/3 size of table
- 61.5% = 1/3 size of table
- 62.5% = 1/2 size of table
- 63.5% = 5/8 size of table
- 65.0% = 7/8 size if table
- 66.0% = Dark table facets
- 67.0% = Dark star facets
When depth percentage becomes greater than 65%, the center of the diamond becomes dark as light refracts through the bottom of the diamond.
The diagram displays the appearance of diamonds with total depth percentages that have proper crown height, crown angles, pavilion depth percentages and pavilion angles.
Proper Total Depth Percentage Does Not Guarantee Proper Cut. Total depth percentage is very important but it can sometimes be misleading. (See diagram below) Total depth percentage is a representation of a diamonds overall total depth. As the diagram illustrates, it is possible for two diamonds to have the same depth percentage and be proportioned differently.
Total depth percentage is a combination of many other important elements of diamond cut. These elements include crown height, crown angle, pavilion depth percentage, pavilion angle and girdle thickness. These elements are properly proportioned in ideal cut diamonds.
However, some diamonds with total depth percentages that are in the range of ideal, may be improperly cut and display less brilliance. A diamond with ideal total depth percentage may also have an overly deep bottom, (deep pavilion depth percentage & steep pavilion angles) and have a very low top, (low crown height & shallow crown angle.) A simpler example would be two men that are six feet tall. One man has perfect symmetry. His upper body is in proper proportion to his lower body. The other man has very long legs and a short waist.
Droste's Certified Gemologist-Appraisers carefully examines every diamond to ensure that crown height, crown angles, pavilion depth percentage and pavilion angles are within the ranges of ideal to very fine quality before it is shipped to you.
Droste's Gemological Laboratory is accredited by the American Gem Society (AGS) and is equipped with a Sarin proportion analyzer, the same non contact optical measuring device used by GIA to measure diamond proportions. Certified-Plus Diamonds does not ship a diamond until cut quality is confirmed to be very fine or ideal cut and all elements of cut are discussed with you. Selecting a diamond without the assurance of these important elements of cut is not advisable.
Droste's is unmatched in quality assurance and lower diamond prices. Don't take chances or waste time, select your diamond from knowledgeable experts you can trust. Droste's Certified Gemologist-Appraisers will be happy to answer any questions you may have in regards to selecting a properly cut diamond.