The spectroscope is an important tool of the modern gemologist.This
concerns the infrared or near infrared spectroscopes.
A handheld spectroscope for visible light shows the absorption
lines of the elements involved in producing its color.
It helps to separate ruby (chrome) against red or pink sapphire
(iron) to name only one example.
This toolrequires a good training and an appropriate light source. Colorless
stones show no absorption spectrum.
The sunlight shows a typical absorption spectrum, the
Fluorescence lamps show an emission spectrum.
For demonstration you may examinate besides gemstones also liquids
or flames colored by metal-salts.