The diamond table is one of the most critical parts of the anatomy of a diamond. It directly impacts the ease of viewing, the cut’s quality, and its worth. In this article, Afshin Shaddiae will teach you everything you’ll need to know about the table facet of a diamond.
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What Is the Diamond Table?
The diamond table is the flat facet that rests at the top of a step-cut or brilliant-cut diamond. When looking at the diamond from the side, the flat surface at the top will literally resemble a table. The table is almost always the largest facet of a diamond.
The diamond table also plays a vital role in determining the quality of the diamond cut. A diamond with a superior cut will have a specific table percentage, and anything that falls too high or too low will negatively impact the stone’s desirability. See below.
Unlike many other diamond-related measurements, the table is measured as a percentage compared to the overall diamond width. If a diamond has an overall measurement of 10mm and the table measures 6mm across, the table measurement will be 60%.
Deeper Explanation: The diamond’s cut refers to the gem’s proportions, symmetry, and polish rather than its shape. The cut of a diamond has three critical effects on its appearance: brilliance (the brightness of the light reflected and refracted), fire (the dispersal of light into color flashes), and scintillation (the sparkle that is seen when the diamond is moved). The table percentage will tremendously impact all three critical effects.
Ideal Measurements for the Diamond Table
As mentioned above, the diamond table is measured as a percentage and not with a set number. Additionally, the ideal measurements that may get an Excellent from GIA will fall within a range of percentages, as shown below. Of course, to get an excellent grade, the ideal depth will also have to match the table percentage.
| Ideal Table Percentage | |
|---|---|
| Round Brilliant Cut | 52% – 62% |
| Princess Cut | 65% – 75% |
| Cushion Cut | 55% – 66% |
| Emerald Cut | 57% – 72% |
| Asscher Cut | 57% – 71% |
| Oval Cut | 53% – 65% |
| Pear Shape | 53% – 66% |
| Marquise Cut | 54% – 64% |
| Rose Cut | Not Applicable |
Good Tables vs. Bad Tables
Although trying to determine the table percentage without a gauge and a calculator is nearly impossible, identifying a good-cut diamond is surprisingly easy.
Diamonds that aren’t cut properly and have table and depth that are off will look “dead” and “flat”. The characteristic sparkle that you will expect from a diamond will be gone.
Below is an example of a round-cut diamond with a 69% table surface. The diamond looks entirely dead and lifeless:
Here’s an example of a round diamond with a table percentage of 50%:
As you can see, unless the table percentage is within the correct bracket (and the depth is also correct), the diamond will not sparkle correctly and will look horrible.
Diamond Table and Diamond Depth
Although this article is about the diamond table, it is important to understand that there is an equally important and equally important factor: diamond depth. The diamond depth refers to the diamond height from the table to the cutlet.
The diamond depth and table are used to calculate the diamond cut. Together, they give us the information we need to determine the diamond’s overall sparkle.
Typically, a diamond’s cut is graded using the GIA grading system. There are five GIA cut grades: Excellent, Very Good, Good, Fair, and Poor.
Diamond Table for Antique Diamonds
Antique diamonds are very different from modern diamonds, and the standards against which they were measured are very different from what the GIA currently uses for modern diamonds.
Therefore, when GIA grades antique diamonds, they usually grade the cut as “fair” or “poor.” This hasn’t stopped antique diamond enthusiasts at all. It startles them at first, but once they understand that this is how antique diamonds are usually graded, they quickly get over it.
The diamond table for antique diamonds will usually vary between 50% – 55%, but it will not be uncommon to see an antique diamond that is graded under 50%.
Frequently Asked Questions
Diamond Table Width vs. Total Diamond Width
The diamond table width is the mm length between the length between one edge of the diamond table and the opposite side of the diamond table. The total diamond width is the mm length between the length between one edge of the diamond and its opposite side. Both of these measurements will be written in mm form.
The diamond table amount, though, will always be written in percentage form.
How to Find Table Width on GIA?
The table percentage amount will be found in the “proportions” section of the GIA certificate, as shown in the diagram above. It will be the amount directly above the center of the diamond. In the example above, the diamond table shows 56%.
The cut grading will be in the left column of the GIA report in the “Grading Results” section.
How to Measure the Diamond Table from Home
You will need a digital caliper and a calculator to measure the diamond table from home.
- Step 1: Measure the distance in mm from one corner of the table to the opposite corner (the furthest away corner of the table). Precision is critical.
- Step 2: Measure the distance in mm from the edge of the diamond to the opposite edge on the other side of the diamond.
- Step 3: Use the calculator (or Google) to create a percentage of how much of the diamond radius line the diamond table takes up.
This technique will work for regular diamonds. Fancy-cut diamonds will have a far more complex measurement.
Do Rose Cuts Have a Table?
No. Rose-cut diamonds do not have a table. They are distinguishable by their domed top and flat base, and although there are six flat facets at the top of the diamond, none of them are called the table.
Although we did our best to explain everything you need to know about diamond tables, we understand that this topic can be confusing, even for industry experts.
If you have any questions or if you’re looking to buy your diamond, please don’t hesitate to contact us. We will respond within one business hour.
