Information on the Treatment of Gemstones and Pearls

Some gemstones may have undergone traditional gemstone treatments, such as heating or the use of colorless liquids intended to enhance their appearance. Pearls may also have undergone a bleaching treatment.

However, the following stones undergo specific treatments that differ from traditional gemstone treatments:

• Black diamond: treatment by heating and irradiation.
• Blue topaz: irradiation treatment.
• Pink topaz: coating treatment.