The gem treatment aims to improve their color and to increase their clarity. Some practices are ancestral and very widespread. It is question of a vast and complex subject. The interpretation of the importance and even of the seriousness of some treatments vary according to the country.
However that may be in accordance with legislation differences, the customers should benefit of the most obvious information so as to choose with full knowledge of the facts. Besides, the occasionally devasting effect of some treatments have a considerable influence on the value of the gems.
Only heating treatment without chemical substance addition is commercially accepted, because it does not add anything to the stone that it already has in a natural state. It’s quite a common practice for a certain number of gems.
The impregnation by a colorless fluid substance especially for emeralds is also a common practice, which does not require the annotation « treated ».
The CIBJO (International Confederation of Jewelry…) defines the standards which are taken up in the decree 2002-65 connected in stones, gems and pearls trade in France. (see articles 1…14).
In short, the display of a stone must be supplemented by the annotation « Treated » in most treatments’ cases. Only the accompaniment to the stone by a gemological certificate emanating from a recognized laboratory will allow a certainty as to the treatments used.