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  GEMSTONE  SPECTRA   COMPARISON 

These are the first sections to be uploaded and additional gems will be inserted in them as we proceed

   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

 SPECTRA OF PRINCIPAL   GEMSTONES

ALEXANDRITE

ALMANDINE GARNET

CHRYSOBERYL

DIAMOND

EMERALD

GREEN JADEITE

PERIDOT

RUBY

RED SPINEL

SYN. BLUE SPINEL  & Co. GLASS

SYN. COLOUR CHANGE CORUNDUM

ZIRCON (High type)

ZIRCON (Low type)

Other pages are under construction

 

Diffraction Spectra of

Sapphire

Colour Properties of Sapphire

Colour

Blue; Greenish blue; Bluish green; Dark green; Pale to deep yellow.

Cause of colour

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

Optical Character

Uniaxial Negative    

Pleochroism

Distinct as two shades of blue, green or yellow. Yellows very weak.

Colour change

No

Spectrum; no polar Calibration in nm.

Three lines at 450; 460; 471; Fine blues may only show the 450 line Bluish greens can display all three and in dark greens and yellows two or three may merge as a single broad band.

Ordinary ray

Any bands present are seen at their strongest in this ray.

Extraordinary ray

Similar but weaker

Alpha ray

Not applicable

Beta ray

Not applicable

Gamma ray

Not applicable

Emission lines

No

Database reference

None yet

Notes

Sri-Lankan pale blues and yellows may only show a very weak 450:

 

Copyright John S.Harris 2000-2010