Weight Correction Percentage Chart
Use these percentages in the weight estimation formula only when the overall girdle thickness is slightly thick or thicker. These figures account for the extra weight tied up in a thick girdle, and are not percentages of the average girdle diameter. You can think of them as flexibility factors that let you refine your estimate. For smaller stones, use the values given for 3.80 mm. For larger stones, use the values for 8.25 mm.
To use the chart, find the line that lists the measurement nearest the stone's average diameter (for fancy cuts, use the width), and follow it until it intersects the girdle thickness column under the description you've chosen for the overall thickness. Take the percentage listed, and add it to 100 percent. This is the figure you'll use in the weight estimation formula.
If, for example, a diamond's average girdle diameter is 5.36 mm and its girdle averages thick, the weight correction would be 3 percent. The 3 percent correction accounts for the extra weight the thick girdle adds.
|
Diameter |
Slightly Thick |
Thick |
Very Thick |
Extremely Thick |
|
3.80 |
3% |
4% |
9% |
12% |
|
3.85 |
3% |
4% |
9% |
12% |
|
3.90 |
3% |
4% |
9% |
12% |
|
3.95 |
3% |
4% |
9% |
12% |
|
4.00 |
3% |
4% |
9% |
12% |
|
4.05 |
3% |
4% |
9% |
12% |
|
4.10 |
3% |
4% |
9% |
12% |
|
4.15 |
2% |
4% |
9% |
12% |
|
4.20 |
2% |
4% |
8% |
11% |
|
4.25 |
2% |
4% |
8% |
11% |
|
4.30 |
2% |
4% |
8% |
11% |
|
4.35 |
2% |
4% |
8% |
11% |
|
4.40 |
2% |
4% |
8% |
11% |
|
4.45 |
2% |
4% |
8% |
11% |
|
4.50 |
2% |
4% |
8% |
11% |
|
4.55 |
2% |
4% |
8% |
11% |
|
4.60 |
2% |
4% |
8% |
10% |
|
4.65 |
2% |
4% |
8% |
10% |
|
4.70 |
2% |
3% |
8% |
10% |
|
4.75 |
2% |
3% |
7% |
10% |
|
4.80 |
2% |
3% |
7% |
10% |
|
4.85 |
2% |
3% |
7% |
10% |
|
4.90 |
2% |
3% |
7% |
10% |
|
4.95 |
2% |
3% |
7% |
10% |
|
5.00 |
2% |
3% |
7% |
10% |
|
5.05 |
2% |
3% |
7% |
10% |
|
5.10 |
2% |
3% |
7% |
10% |
|
5.15 |
2% |
3% |
7% |
9% |
|
5.20 |
2% |
3% |
7% |
9% |
|
5.25 |
2% |
3% |
7% |
9% |
|
5.30 |
2% |
3% |
7% |
9% |
|
5.35 |
2% |
3% |
7% |
9% |
|
5.40 |
2% |
3% |
7% |
9% |
|
5.45 |
2% |
3% |
7% |
9% |
|
5.50 |
2% |
3% |
7% |
9% |
|
5.55 |
2% |
3% |
6% |
9% |
|
5.60 |
2% |
3% |
6% |
9% |
|
5.65 |
2% |
3% |
6% |
9% |
|
5.70 |
2% |
3% |
6% |
9% |
|
5.75 |
2% |
3% |
6% |
9% |
|
5.80 |
2% |
3% |
6% |
8% |
|
5.85 |
2% |
3% |
6% |
8% |
|
5.90 |
2% |
3% |
6% |
8% |
|
5.95 |
2% |
3% |
6% |
8% |
|
Diameter |
Slightly Thick |
Thick |
Very Thick |
Extremely Thick |
|
6.00 |
2% |
3% |
6% |
8% |
|
6.05 |
2% |
3% |
6% |
8% |
|
6.10 |
2% |
3% |
6% |
8% |
|
6.15 |
2% |
3% |
6% |
8% |
|
6.20 |
2% |
3% |
6% |
8% |
|
6.25 |
2% |
3% |
6% |
8% |
|
6.30 |
2% |
3% |
6% |
8% |
|
6.35 |
2% |
3% |
6% |
8% |
|
6.40 |
2% |
3% |
6% |
8% |
|
6.45 |
2% |
3% |
6% |
8% |
|
6.50 |
2% |
3% |
6% |
8% |
|
6.55 |
2% |
3% |
6% |
8% |
|
6.60 |
2% |
2% |
5% |
7% |
|
6.65 |
2% |
2% |
5% |
7% |
|
6.70 |
2% |
2% |
5% |
7% |
|
6.75 |
2% |
2% |
5% |
7% |
|
6.80 |
2% |
2% |
5% |
7% |
|
6.85 |
2% |
2% |
5% |
7% |
|
6.90 |
2% |
2% |
5% |
7% |
|
6.95 |
1% |
2% |
5% |
7% |
|
7.00 |
1% |
2% |
5% |
7% |
|
7.05 |
1% |
2% |
5% |
7% |
|
7.10 |
1% |
2% |
5% |
7% |
|
7.15 |
1% |
2% |
5% |
7% |
|
7.20 |
1% |
2% |
5% |
7% |
|
7.25 |
1% |
2% |
5% |
7% |
|
7.30 |
1% |
2% |
5% |
7% |
|
7.35 |
1% |
2% |
5% |
7% |
|
7.40 |
1% |
2% |
5% |
7% |
|
7.45 |
1% |
2% |
5% |
7% |
|
7.50 |
1% |
2% |
5% |
7% |
|
7.55 |
1% |
2% |
5% |
7% |
|
7.60 |
1% |
2% |
5% |
7% |
|
7.65 |
1% |
2% |
5% |
7% |
|
7.70 |
1% |
2% |
5% |
6% |
|
7.75 |
1% |
2% |
5% |
6% |
|
7.80 |
1% |
2% |
5% |
6% |
|
7.85 |
1% |
2% |
5% |
6% |
|
7.90 |
1% |
2% |
5% |
6% |
|
7.95 |
1% |
2% |
5% |
6% |
|
8.00 |
1% |
2% |
5% |
6% |
|
8.05 |
1% |
2% |
5% |
6% |
|
8.10 |
1% |
2% |
5% |
6% |
|
8.15 |
1% |
2% |
4% |
6% |
|
8.20 |
1% |
2% |
4% |
6% |
|
8.25 |
1% |
2% |
4% |
6% |