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  GEMSTONE SPECTRA

(EXCEL FILES)

COLOURLESS STONES

 CS1

 RED STONES  

   RD1 Dark red

   RD2 Pinkish red

  RD3 Orangy red

RD4 Slightly purplish red

  RD5  Purplish red

PINK STONES 

PK1 Lilac pink

   PK2 Pink and orangy pink

PK3  Brownish and purplish pink

ORANGE STONES

OR1

YELLOW STONES

YL1

GREEN STONES

GN1 Green

GN2 Yellowish and greyish green

GN3 Bluish green

  GN4 Dark and brownish green

BROWN STONES

BN1 Light brown

BN2 Dark brown

BLUE STONES

BL1 Blue

BL2 Greenish blue

BL3 Lavender and indigo blue

VIOLET AND PURPLE STONES

VT - PL Violet and Purple

  Periodically other gemstones will be added to these files

 

 

 

Green, blue and violet Spinel

See my  DECLARATION OF COPYRIGHT

Colour Properties of green, blue and violet Spinel

Colour

Dark green, greenish blue, dark blue to violet. Rarely a cobalt blue.

Cause of colour

Mainly iron. Low iron plus cobalt contributes to finer blues.

Optical Character

Isotropic                   

Pleochroism

Not applicable

Colour change

Violet stones may show a colour shift to purple in tungsten light.

Spectrum; no polar, calibration in nm.

A strong line at 458 and a weaker one at 478 are variable with iron content. Bands at 555(narrow) 585(broad)and 635(broad) vary in intensity being strong in Co. rich stones where iron lines are weak.

Ordinary ray

Not applicable

Extraordinary ray

Not applicable

Alpha ray

Not applicable

Beta ray

Not applicable

Gamma ray

Not applicable

Emission lines

No

Database reference

GN3;BL!;BL2; and BL3

Notes

Cobaltious spinel BLF0856 is a bright red under a Chelsea Filter.

6

Copyright John S. Harris 2000-2016

 

 PRINCIPAL 

SPECTRA OF

COMMERCIAL GEMS

ALEXANDRITE

ALMANDINE GARNET

CHRYSOBERYL

DIAMOND

EMERALD

GREEN JADEITE

PERIDOT

RUBY

BLUE SAPPHIRE

RED SPINEL

  SYN. BLUE SPINEL &  Co. GLASS

SYN. COLOUR CHANGE CORUNDUM

ZIRCON (High type)

ZIRCON (Low type)

Other pages are under construction

COLOUR FILTERS

 (EXCEL FILES)    

CF1 Basic Colour Filters

CF2 Special Colour Filters

EDUCATIONAL C. D.

  A GUIDE TO THE   SPECTROSCOPE