Dispersion Fire Value

Interpolate measured optical dispersion at caller two spectral references, retaining anomalous signed dispersion; no fixed mineral fire value or pulse-dispersion alias.

Description

Optical dispersion compares refractive index at two specified wavelengths.

Optical dispersion compares refractive index at two specified wavelengths. Signed anomalous dispersion should remain visible rather than being clamped.^[1]

Interpolate measured optical dispersion at caller two spectral references, retaining anomalous signed dispersion; no fixed mineral fire value or pulse-dispersion alias.

When to use Dispersion Fire Value

Use this tool to interpolate measured optical dispersion at caller two spectral references, retaining anomalous signed dispersion; no fixed mineral fire value or pulse-dispersion alias.

Prepare the gemstone measurements, spectra or comparison data and any supplied calibration parameters. Check units, reference conditions and record alignment.

How to use Dispersion Fire Value 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 measuredWavelengthsNm, measuredIndices, shortReferenceWavelengthNm, longReferenceWavelengthNm using the field table and calculation rules, then run the tool.
Read referenceIndexDispersion, averageIndexSlopePerNm. 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
measuredWavelengthsNm	Measured wavelengths nm	list of number	Required
measuredIndices	Measured indices	list of number	Required
shortReferenceWavelengthNm	Short reference wavelength nm	number	Required
longReferenceWavelengthNm	Long reference wavelength nm	number	Required

Use positive increasing measured wavelengths in nm, aligned positive indices and increasing positive reference wavelengths within coverage. Linearly interpolate both indices and return signed dispersion and mean index slope per nm.

dispersion=n(short wavelength)−n(long wavelength); slope=(nlong−nshort)/(long−short)

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
referenceIndexDispersion	Reference index dispersion	number
averageIndexSlopePerNm	Average index slope per nm	number

json

{
  "input": {
    "measuredWavelengthsNm": [
      400,
      700
    ],
    "measuredIndices": [
      1.6,
      1.5
    ],
    "shortReferenceWavelengthNm": 400,
    "longReferenceWavelengthNm": 700
  },
  "output": {
    "referenceIndexDispersion": 0.10000000000000009,
    "averageIndexSlopePerNm": -0.00033333333333333365
  }
}

Limitations and assumptions

No extrapolation, mineral fire lookup or pulse-dispersion model is included.

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 Refractive Index Snell: Infer optical index from independent measured refracted rays and incident-medium index; no mineral identity, normal-incidence division or ocean-wave speed/refraction alias. For a complementary task, use Birefringence Delta RI: Audit observed directional RI spread against caller resolution, not an inferred complete principal-index birefringence or mineral diagnostic; unobserved directions may hide larger spread.

References

Dispersion Fire Value — tool.io

Similar or alternative tools

Refractive Index Snell
Infer optical index from independent measured refracted rays and incident-medium index; no mineral identity, normal-incidence division or ocean-wave speed/refraction alias.
Birefringence Delta RI
Audit observed directional RI spread against caller resolution, not an inferred complete principal-index birefringence or mineral diagnostic; unobserved directions may hide larger spread.