Girdle Thickness Percentage
Retain circumferential girdle variation and actual perimeter-weighted thickness relative to caller diameter, rather than one unrepresentative spot percentage or fracture-risk grading.
Description
Girdle thickness varies around a stone's perimeter.
Girdle thickness varies around a stone's perimeter. Samples representing different arc lengths require perimeter weighting rather than one spot percentage.1
Retain circumferential girdle variation and actual perimeter-weighted thickness relative to caller diameter, rather than one unrepresentative spot percentage or fracture-risk grading.
When to use Girdle Thickness Percentage
Use this tool to retain circumferential girdle variation and actual perimeter-weighted thickness relative to caller diameter, rather than one unrepresentative spot percentage or fracture-risk grading.
Prepare the gemstone measurements, spectra or comparison data and any supplied calibration parameters. Check units, reference conditions and record alignment.
How to use Girdle Thickness Percentage and understand its results
- Prepare the gemstone measurements, spectra or comparison data and any supplied calibration parameters. Check units, reference conditions and record alignment.
- Enter girdleThicknessSamplesMm, representedPerimeterLengthsMm, referenceGirdleDiameterMm using the field table and calculation rules, then run the tool.
- Read perimeterWeightedGirdleThicknessPercent, girdleThicknessPercentBounds, observedCircumferentialThicknessRangeMm. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| girdleThicknessSamplesMm | Girdle thickness samples mm | list of number | Required |
| representedPerimeterLengthsMm | Represented perimeter lengths mm | list of number | Required |
| referenceGirdleDiameterMm | Reference girdle diameter mm | number | Required |
Pair nonnegative thickness samples in mm with positive represented perimeter lengths and positive reference diameter. Return weighted percentage, minimum/maximum percentages and observed thickness range in mm.
Paired lists must be nonempty and have equal lengths.
weighted thickness percent=100 × Σ(thickness × represented length)/Σlength/reference diameter Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| perimeterWeightedGirdleThicknessPercent | Perimeter weighted girdle thickness percent | number |
| girdleThicknessPercentBounds | Girdle thickness percent bounds | list of number |
| observedCircumferentialThicknessRangeMm | Observed circumferential thickness range mm | number |
{
"input": {
"girdleThicknessSamplesMm": [
0.1,
0.3
],
"representedPerimeterLengthsMm": [
1,
3
],
"referenceGirdleDiameterMm": 10
},
"output": {
"perimeterWeightedGirdleThicknessPercent": 2.4999999999999996,
"girdleThicknessPercentBounds": [
1,
3
],
"observedCircumferentialThicknessRangeMm": 0.19999999999999998
}
}Limitations and assumptions
Unobserved perimeter and fracture risk are not inferred. The diameter reference is caller-defined.
Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Total Depth Percentage: Audit measured total depth against independently measured crown/girdle/pavilion depth ledger and girdle diameter; closure error remains signed, not another solitary component-percentage alias. For a complementary task, use Volume of Round Brilliant: Evaluate closed coaxial crown-frustum/girdle-cylinder/pavilion-frustum envelope volume including table/culet under supplied geometry; approximation is not true individual faceted round-brilliant geometry or carat weight.
References
-
Girdle Thickness Percentage — tool.io
Similar or alternative tools
- Total Depth Percentage
Audit measured total depth against independently measured crown/girdle/pavilion depth ledger and girdle diameter; closure error remains signed, not another solitary component-percentage alias.
- Volume of Round Brilliant
Evaluate closed coaxial crown-frustum/girdle-cylinder/pavilion-frustum envelope volume including table/culet under supplied geometry; approximation is not true individual faceted round-brilliant geometry or carat weight.