Diamond Cut Study
OctoNus Diamond
Cut Initiative
Rough and Polish diamond movies
Master Stone Set
Study of Interdependence:
Fancy-color Diamond Appearance, Cut, and Lighting Conditions
Fancy-Color Diamonds:
Better Color Appearance by Optimizing Cut

1 Content
2 Color optimization method
3 Diamond absorption spectra
4 Two representations of colors
5 A good fancy colored diamond should be bright and saturated
6 Color potential of a colored diamond plate
7 DiamCalc ray tracing options and photorealistic images
8 One spectrum different cuts and different lightings
9 Process flow
10 Exploring rough diamond potential
11 Rough allocation example
12 Different allocation plans
13 Automatic color optimization
14 Optimization by color
15 Optimization by contrast
16 Optimization results
17 Computer-aided color optimization
18 Expert considerations
19 The final stage: expert decision
20 Verification of the technology: CZ material
21 Real photos of CZ stones and photorealistic images based on Helium scanned 3d models
22 Verification on fancy shapes CZ
23 Summary
24 More information about diamond cut study technologies
25 Terms of colorimetry science (Hunt, 2004)
26 Acknowledges
27 References
Computer modeling of gemstones for improvement of their color appearance
Visible adsorption spectra and DiamCalc-files of colored gem materials
DiamCalc Internal Cuts gallery
External Cuts gallery (Dll)
Diamond cuts gallery
Optimization results

Chroma value is changing with lighting conditions and can not be easily transformed into a certain color grade.

Color grade borderlines are also changed with hue.

C Chroma, RC relative contrast


  Office light, black background Dialite light Dialite light
Tilted 15 up
Before color optimization:

4,02 ct
Cr = 36 P = 43

Office light: C = 20.24, RC = 0.64
Dialite light: C = 32.51, RC = 0.21

After color optimization:

5,21 ct
C = 48 P = 47.5

Office light: C = 28.90, RC = 0.54
Dialite light: C = 31.94, RC = 0.18

Then an expert works with optimization results for each shape. It different lighting conditions one can compare stones before and after optimization:

  • by photorealistic images
  • by color metrics

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