Gemmology Measurements

Colour is one of the value determining factors in diamonds.

Natural and treated diamonds can be measured in the spectral range of 400-750nm. Interesting wavelengths can be found in the absorption spectrum at 415nm and 478nm (Type Ia diamond natural diamond), where artificial diamonds show no absorption peaks. For treated diamonds, artificial colouring can be measured at a wavelength of 592 or 741nm.

The value difference between a natural and treated diamond may be as high as a factor 10. Of course other gemstones may also be measured such as ruby, alexandrite, sapphire, etc.

A typical setup for gemstone measurement is shown in the illustration above.

Typical components used in gemstone measurements