Visible adsorption spectra and DiamCalc-files of colored gem materials

Sergey Sivovolenko, OctoNus
Yuri Shelementiev, Diamond Design
Roman Serov, Moscow State University Gemological Center

Colored gem materials:

  • Amethyst
  • Corundum
  • Cubic Zirconium
  • Diamond
  • Emerald
  • Sapphire
  • Synthetic diamond
  • Topaz
  • Quartz

Spectral data was obtained with SF-56A spectrophotometer in the 370 - 770 nm range, 1 nm step in Moscow State University Gemological Center. Spectra were recorded through two opposite parallel windows of the sample in room temperature.

All spectral data recorded on the spectrometer were converted into an adsorption coefficient in mm-1 taking into consideration the thickness of the sample and the refraction coefficient of the gem material. All spectral data for natural (untreated) colored diamonds was averaged with 20 nm step.

A Prism model with similar thickness as used for spectral data collection was selected in DiamCalc (for polished stones - Helium scanned 3D model of radiant cut). Light conditions for the prism in DiamCalc files: one transmitted source type A (for polished stones 3D models: the standard Dialite DiamCalc lighting).

Corresponding absorption spectra used for modeling are available in the Microsoft Excel format.

Amethyst

Amethyst violet new!
A moderate violet natural amethyst spectrum obtained through 10 mm thick plate along an arbitrary direction.
Open DiamCalc file
DiamCalc file amethyst_prizm.dmc MS Excel file amethyst.xls DiamCalc file amethyst.dmc
 

Corundum

Corundum Red direction 1
A red synthetic corundum spectrum obtained through 10 mm thick plate along an arbitrary direction.
Open DiamCalc file
DiamCalc file Corundum_Red_direction1_prizm.dmc MS Excel file Corundum_Red_direction1.xls DiamCalc file Corundum_Red_direction1.dmc
 
Corundum Red irection 2
Spectrum of the same red material obtained through the 11 mm thick plate with another arbitrary direction. Red color of that stone is related with Cr3+ adsorption features.
Open DiamCalc file
DiamCalc file Corundum_Red_direction2_prizm.dmc MS Excel file Corundum_Red_direction2.xls DiamCalc file Corundum_Red_direction2.dmc
 
Corundum Orange Red direction 1
An orange-red synthetic corundum spectrum obtained through 10 mm thick plate along an arbitrary direction.
Open DiamCalc file
DiamCalc file Corundum_OrRed_direction1_prizm.dmc MS Excel file Corundum_OrRed_direction1.xls DiamCalc file Corundum_OrRed_direction1.dmc
 
Corundum Orange Red direction 2
Spectrum of the same material obtained through the 11.5 mm thick plate along another direction. Cr3+ features also present in spectrum of this stone, but the concentration of Cr is much lower.
Open DiamCalc file
DiamCalc file Corundum_OrRed_direction2_prizm.dmc MS Excel file Corundum_OrRed_direction2.xls DiamCalc file Corundum_OrRed_direction2.dmc
 
Corundum Orange direction 1
An orange synthetic corundum spectrum obtained through 9 mm thick plate along an arbitrary direction.
Open DiamCalc file
DiamCalc file Corundum_Or_direction1_prizm.dmc MS Excel file Corundum_Or_direction1.xls DiamCalc file Corundum_Or_direction1.dmc
 
Corundum Orange direction 2
Spectrum of the same material obtained through the 10 mm thick plate along another direction. No Cr3+ related features present. Color origin of that stone is undefined.
Open DiamCalc file
DiamCalc file Corundum_Or_direction2_prizm.dmc MS Excel file Corundum_Or_direction2.xls DiamCalc file Corundum_Or_direction2.dmc
 

Cubic Zirconium

Cubic Zirconium Green
A green cubic zirconium (CZ) spectrum obtained through 18 mm thick plate. Color of that stone is related with REE adsorption.
Open DiamCalc file
DiamCalc file CZ_Green_prizm.dmc MS Excel file CZ_Green.xls DiamCalc file CZ_Green.dmc
 
Cubic Zirconium Red
A red CZ spectrum obtained through 20 mm thick plate.
Open DiamCalc file
DiamCalc file CZ_Red_prizm.dmc MS Excel file CZ_Red.xls DiamCalc file CZ_Red.dmc
 
Cubic Zirconium Violet
A violet CZ spectrum obtained through 22 mm thick plate. Color of that stone is related with REE adsorption.
Open DiamCalc file
DiamCalc file CZ_Violet_prizm.dmc MS Excel file CZ_Violet.xls DiamCalc file CZ_Violet.dmc
 
Cubic Zirconium Yellow new!
A yellow cubic zirconium (CZ) spectrum obtained through 4 mm thick plate. Color of that stone is related with REE adsorption.
Open DiamCalc file
DiamCalc file CZ_Yellow_prizm.dmc MS Excel file CZ_Yellow.xls DiamCalc file CZ_Yellow.dmc
 

Diamond

Diamond Dark Orange Brown
A dark orange-brown natural diamond (untreated) spectrum obtained through 3.6 mm thick plate. This diamond is Ia type and it can be assumed that its color is connected with dislocations.
Open DiamCalc file
DiamCalc file Diamond_Dark_OrangeBrown_prizm.dmc MS Excel file Diamond_Dark_OrangeBrown.xls DiamCalc file Diamond_Dark_OrangeBrown.dmc
 
Diamond Fancy Deep Orange Brown
A fancy deep orange-brown natural diamond (untreated) "Diamond_Fancy_Deep_Orange_ Brown" spectrum obtained through 4.15 mm thick plate. This diamond is Ia type and it is assumed that its color is also connected with dislocations.
Open DiamCalc file
DiamCalc file Diamond_Fancy_DeepOrBr_prizm.dmc MS Excel file Diamond_Fancy_DeepOrBr.xls DiamCalc file Diamond_Fancy_DeepOrBr.dmc
 
Diamond Fancy Yellow
A fancy yellow natural diamond (untreated) spectrum obtained through 4 mm thick plate. This diamond is natural Ib type and its color is related with C-centers absorption.
Open DiamCalc file
DiamCalc file Diamond_Fancy_Yellow_prizm.dmc MS Excel file Diamond_Fancy_Yellow.xls DiamCalc file Diamond_Fancy_Yellow.dmc
 
Diamond Fancy Yellow Lemon
A fancy greenish-yellow natural diamond (untreated) spectrum obtained through 6.76 mm thick plate. Color of that stone is related with two broad bands on 478 and 560 nm.
Open DiamCalc file
DiamCalc file Diamond_Fancy_YellowLemon_prizm.dmc MS Excel file Diamond_Fancy_YellowLemon.xls DiamCalc file Diamond_Fancy_YellowLemon.dmc
 
Diamond Yellow new!
A light yellow natural diamond spectrum obtained through 3.5 mm thick plate along an triad axis direction. This diamond is Ia type and its color is related with N3-N2 centres.
Open DiamCalc file
DiamCalc file Diamond_Yellow_prizm.dmc MS Excel file Diamond_Yellow.xls DiamCalc file Diamond_Yellow.dmc
 

Sapphire

Sapphire new!
A blue natural sapphire "Sapphire" spectrum obtained from Mineral Spectroscopy Server visible spectra database* and then adjusted. Sapphire color is related with Ti-Fe presence.
Open DiamCalc file
DiamCalc file Sapphire_prizm.dmc MS Excel file Sapphire.xls DiamCalc file Sapphire.dmc
 

Emerald

Emerald new!
A green natural emerald spectrum is one of DiamCalc standard spectra. Emerald color is related with Cr presence.
Open DiamCalc file
DiamCalc file Emerald_prizm.dmc MS Excel file Emerald.xls DiamCalc file Emerald.dmc
 

Synthetic diamond

Yellow synthetic diamond
A yellow synthetic diamond spectrum obtained through 5 mm thick plate. This diamond is Ib type and its color is related with C-centers absorption.
Open DiamCalc file
DiamCalc file Synthetic_diamond_Yellow_prizm.dmc MS Excel file Synthetic_diamond_Yellow.xls DiamCalc file Synthetic_diamond_Yellow.dmc
 

Topaz

Topaz parallel C-axis direction
A blue irradiated topaz "Topaz_paralC" spectrum obtained through 13 mm thick plate along parallel C-axis
Open DiamCalc file
DiamCalc file Topaz_paralC_prizm.dmc MS Excel file Topaz_paralC.xls DiamCalc file Topaz_paralC.dmc
 
Topaz perpendicular C-axis direction
Spectrum of the same material obtained through the 11.5 mm thick plate in the perpendicular C-axis direction.
Open DiamCalc file
DiamCalc file Topaz_perpC_prizm.dmc MS Excel file Topaz_perpC.xls DiamCalc file Topaz_perpC.dmc
 

Quartz

Quartz through the zone with weaker color
A yellow color-treated natural quartz spectrum obtained through 12 mm thick plate perpendicular C-axis of the stone recorder through the zone with weaker color.
Open DiamCalc file
DiamCalc file Qtz_Yellow_weak_perpC_prizm.dmc MS Excel file Qtz_Yellow_weak_perpC.xls DiamCalc file Qtz_Yellow_weak_perpC.dmc
 
Quartz through the zone with more yellow color
Spectrum of the same material obtained through the same plate but through the zone with more yellow color. Color of that stone is related with Fe3+ presence.
Open DiamCalc file
DiamCalc file Qtz_Yellow_intence_perpC_prizm.dmc MS Excel file Qtz_Yellow_intence_perpC.xls DiamCalc file Qtz_Yellow_intence_perpC.dmc
 

All spectral data recording, calculations and DiamCalc modeling done at Moscow University (MSU) Gemological Center www.gemology.ru

Visible adsorption spectra and DiamCalc-files of colored gem materials