The PL-Inspector (PhotoLuminescence Inspector) allows observation of fluorescence and phosphorescence from short-wave (SW) and long-wave (LW) ultra-violet illumination. These observations can help a gemmologist determine whether a diamond or gem is synthetic or treated. The colour and intensity of the fluorescence provides a useful indicator, with a common test being whether the SW intensity is brighter than the LW, thereby suggestive of a synthetic diamond.

The PL-Inspector has an inspection viewing area of 15 x 15 mm. (For parcels of stones or jewellery pieces, the Jewellery Inspector provides a 50 x 50 mm viewing area.) Coupled with an optional battery power pack it becomes a pocket travel unit, ideal for trade events - to identify, for example, if a diamond is synthetic or treated.

Click here to view a yellow diamond that shows blue fluorescence under ultra-violet light - and see how it is is possible to distinguish between a natural and synthetic diamond. For practical workshops on natural, treated and synthetic diamonds and how to use the PL-inspector and other portable instruments visit

A quick guide to using a PL-Inspector can be downloaded here (PDF file).

Use the Gemetrix Mobile App to allow your smartphone's camera to take and compare PL-Inspector images.

PL-Inspector Features are

  • Bright illumination
  • Portable, weighing only 300 g
  • 12V battery or mains power
  • Viewing magnifier lens
  • Smart-phone compatible

Suitable for viewing

  • Melee
  • Mounted stones
  • Rough diamonds
  • Other gems - large and small

How to Buy

  • Please contact us for a list of stockists.
  • You can also purchase directly from Gemetrix, please contact us with any enquiries.
  • We ship worldwide.
  • We accept PayPal


  • Short-wave ultra-violet at 255 nm.
  • Long-wave ultra-violet at 365 nm.