The Inspectrum provides a convienient and portable way to perform optical spectroscopy on gems. It illuminates a gem under evaluation with white light and then analysing which wavelengths have been transmitted or absorbed after interacting with the gem.


The instrument comprises a visible light spectrometer combined with a 405 nm laser and white light source. It provides both fluorescence and transmission spectra from gems.

  The Inspectrum has been specifically designed for use with facetted diamonds, especially for the detection of lab-grown and treated diamonds. It is unique in several respects:
  • 1) Features both a visible transmission and a PL (405 nm) capability in the one unit without having to relocate the sample
  • 2) Enhanced transmission sensitivity in the 415 nm and 700 – 750 nm region
  • 3) Able to record transmission spectra for mounted gems and reflection spectra for stones (e.g. jade)
  • 4) Highly compact and portable
  • 5) Can be powered by an external 12V battery pack (8 x AA batteries)
  • 6) Affordable low price.
A common test for diamond ID is to observe features, such as the 415 nm (natural) line in a PL spectrum. However for diamonds that are not fluorescent, such spectrum is not attainable. A transmission spectrum will reveal the 415 nm feature as absorption rather than emission. With a flick of a switch an Inspectrum can be converted to visible transmission mode when a 415 nm and other absorption lines can be observed.

A PC is required to interface with the spectrometer and to be able to save spectra as txt files and be able to compare with some reference spectra.

Examples of a PL and transmission spectrum are shown opposite.