The bleaching of pearls should be disclosed and described all transactions, CIBJO’s Pearl Commission has recommended during it session at the 2024 CIBJO Congress in Shanghai.

While CIBJO has long recommended describing treatments in transactions, the organisation has now added the provision that bleaching, a commonplace practice for example in Japanese akoya pearls, shall be described in trade along the whole supply chain. 

The CIBJO Commmission also clarified that drilling of natural pearls shall be described in transactions,following questions received internally from CIBJO members, Pearl Commission President Kenneth Scarratt said.

Often treatments pertaining to natural pearls, such as drilling, can reduce weight, which links to their value. In cultured pearls, value is linked to their size, not weight. Holes caused by drilling can widen over time, reducing the weight of a natural pearl.

“It is in the best interests and responsibility of the trade for consumers to be fully informed with regard to treatments applied to pearls,” the CIBJO Special Report on Pearls said.

“Treatments may impact a pearl’s value as they are often not permanent or may require special care,” it added.”The seller should therefore inform the purchaser about the treatments.”

Drilling of natural pearls must be stated especially  where drill holes in natural pearls are hidden from view by a setting. Purchasers should also  informed of the condition of pearls, eg plugged, narrow, wide.

But drilling of cultured pearls may not require such explanations, according to the CIBJO recommendations. This is because the drilling of cultured pearls does not impact their size, which is a determinant of the value of cultured pearls.

The latest recommendations were agreed by delegates attending the 2024 CIBJO Congress in Shanghai, China, who included a number of experienced pearl dealers from around the world.

Separately, a new document has been uploaded to the CIBJO website, entitled “The Environmental, Social and Economic Impact of Natural and Cultured Pearls.”

The CIBJO Congress noted the latest version of the Pearl Standard 2020, developed by Japanese trade associations, and presented to plenary a new Italian translation of CIBJO’s pearl guide to classify natural and cultured pearls in international trade.

CIBJO recommendations to describe treatments apply to all materials used in the jewellery industry.

If a pearl, for example, is suspected of having been subject to treatments, it is prudent for this to be declared in transactions, according to CIBJO guidelines.