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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

 

 

Peridot

See my  DECLARATION OF COPYRIGHT

Colour Properties of Peridot

Colour

Yellowish green to brownish green

Cause of colour

Ferrous iron

Optical Character

Biaxial positive

Pleochroism

Pale shades of green, yellowish green and brownish green weak!

Colour change

No

Spectrum; no polar Calibration in nm.

Three evenly spaced weak narrow bands at 453; 573 and 495; Darker stones may show a weak diffuse bands at 529 and 635. 

Ordinary ray

Not applicable

Extraordinary ray

Not applicable

Alpha ray

Pale green; Three main bands are present but weak.. 453 is broadest

Beta ray

Yellowish green;493 extends to 497 with some transmission between; the 473 and 453 strengthen.. A weak 529 may be detected.

Gamma ray

Brownish green Three main bands are stronger and 493 extends to 495;

Emission lines

No

Database reference

GN2 - Yellowish green gems

Notes

Use a polarizing filter and locate gamma to intensify the three bands

Copyright John S. Harris 2000-2016

 

 SPECTRA OF

 PRINCIPAL 

COMMERCIAL GEMS

ALEXANDRITE

ALMANDINE GARNET

CHRYSOBERYL

DIAMOND

EMERALD

GREEN JADEITE

RUBY

BLUE SAPPHIRE  

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