The scales of the French Gemmology Laboratory are for regulated use. They are installed on a station that absorbs the surrounding vibrations. They are METTLER brand and provide weights to the ten thousandths of a unit.
- Mass determination (in carat or gram)
- Identification of hydrophane opals, as measured by mass variation (dry or immersed).
- Density calculation. The mass of natural gems is provided in carats, the mass of synthetic products is provided in grams.