Etymological, "Gemmology" means "Study of Gems".

améthystes  pierre rose  péridot

The mysterious charm of gems, their  exquisite colours  and their fires would be sufficient to make them precious; but their rarity, their hardness and their durability make them more valued.

An experienced gemmologist could determine most stones with a thorough examination with a magnifying glass. But now days, with so many synthetic stones, imitations, and fakes, it is impossible; 

in many cases instruments help to identify stones correctly.


Necessary equipment to identify stones:
  • A magnifying glass.
  • A polariscope to determine optic character of stones. 
  • A refractometer to determine refractive indice and birefringence' measures.
  • A dichroscope to observe pleochroïc colours.
  • A spectroscope to  decompose the light on a spectrum.
  • A Chelsea filter will allow only extreme red and yellow-green.
  • A thermic conductimeter to measure heat's transfer of substances.
  • Density liquides help to identify gemstones' spécific gravity.
  • Ultraviolets'lights to observe luminescence, a stone reaction under UV rays, away from any other light.
  • A binocular to identify inclusions.

Methodes and instruments mainly concerne physical property measurements, caracteristics of several precious stones.  

Minerals' properties depend of two factors:

If the results are still incertain, you can ask for a well known laboratory's services, where research worker have
accurate, sophisticated and costly equipment. 

Cécile CHANCEREL - 19, avenue St-Hubert - 44500 LA BAULE - FRANCE - Phone : 33 (0) ou 33 (0)