Spectroscope

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Revision as of 06:07, 7 September 2006 by Doos (talk | contribs) (Absorption)
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Doos 03:37, 28 July 2006 (PDT)

The spectroscope is a tool to examin which parts of white light are absorbed by a gemstone (as well as in other materials).
Materials can absorb parts of the electromagnetic spectrum and when the absorbed parts fall with in the visible range, that absorbed part will influence the color of the material.
When a gemstone is observed with a spectroscope, the absorbed parts show as dark lines and/or bands in the spectroscope image.

OPL teaching diffraction grating spectroscope on stand (left) and prism spectroscope with adjustable slit (right)

There are two types of spectroscopes used in gemology:

  1. Prism spectroscopes (based on dispersion)
  2. Diffraction grating spectroscopes (based on diffraction)


Basic

Absorption

absorption of all wavelengths except red
absorption of all wavelengths except red and blue


Types of spectroscopes

Prism spectroscope

prism spectrum


prism spectrum with scale in nm


Diffraction grating spectroscope

File:Spectrum1.jpg
diffraction grating spectrum


File:Spectrum2.jpg
diffraction grating spectrum with scale in nm


Related topics

Aknowledgements