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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

 

 

Blue Sapphire

See my  DECLARATION OF COPYRIGHT

Colour Properties of  Blue Sapphire

Colour

Pale to royal blue and dark blue;

Cause of colour

Titanium-Iron transfer charge); Iron (Fe.2+- Ti4+) and Fe3+-Fe3+

Optical Character

Uniaxial Negative    

Pleochroism

Distinct as two shades of blue and  pale or greenish blue

Colour change

Possible in pale blue stones which contain a small amount of Cr.

Spectrum; no polar Calibration in nm.

Pale blues have a weaker absorption with possibly a fluorescence line in the deep red. Saturated blue stones absorb strongly from deep red to yellowish green with a faint line at 450 in the deep blue. Dark blues  may show additional lines at 460 and 471in the blue.which may merge with the 450 as a broad band.

Ordinary ray

Absorption is strongest in this ray.

Extraordinary ray

Absorption is weaker

Alpha ray

Not applicable

Beta ray

Not applicable

Gamma ray

Not applicable

Emission lines

Possibly in pale bluestones which contain Cr.

Database reference

Excel files BL1; BL2 and BL3

Notes

Sri-Lankan pale blues may only show a very weak line at 450:

 

 

 

 

 

 

 

 

 

 

 

 

Copyright John S. Harris 2000-2016

 

 

SPECTRA OF

 PRINCIPAL 

COMMERCIAL GEMS

ALEXANDRITE

ALMANDINE GARNET

CHRYSOBERYL

DIAMOND

EMERALD

GREEN JADEITE

PERIDOT

RUBY

RED SPINEL

GREEN & BLUE 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