Editor’s Note
This article highlights a crucial, yet often overlooked, aspect of the gemstone industry: the near-universality of treatments. As expert Julia Griffith details, from rubies to sapphires, most stones undergo some form of enhancement. For consumers, understanding this standard practice is key to making informed purchases and appreciating the true nature of these beautiful objects.
The Gemological Association of Great Britain estimates that 98 percent of rubies are treated; heated, glass-filled or otherwise subjected to diffusion and flux techniques. Blue topaz is almost entirely treated, sapphires are 95 percent treated in some way by either glass filling, diffusion or heat treatment, while citrines are often heat-treated, according to gemology and diamond tutor Julia Griffith. Aquamarines are heat-treated, emeralds are often filled with oil or resins to hide fractures and turquoise is resin-coated. (Enhanced coloured diamonds are “not common,” however, Griffith says, and any treatment of diamonds is usually clearly described at point of sale).
According to the Gemological Institute of America which examines more than two million diamonds, coloured stones and pearls each year for grading and analysis, these treatments range from bleaching to surface coating to dyeing to irradiation (where gems are exposed to an artificial source of radiation to change their colour). Laser drilling is also used to remove dark spots on stones, while lattice diffusion, where an element such as beryllium is penetrated into rubies and sapphires to enhance the colour is common.
And yet disclosure isn’t always the norm. In a competitive market worth $310 billion according to Euromonitor, the potential negative sales impact of disclosing treatments is often seen as a commercial liability. It’s a stance that may surprise consumers increasingly interested in transparency and ethics.
The treatment of gemstones has been going on for centuries but the increasingly technologically-savvy treatments — and the difficulty in detecting these — makes things ever more complicated and often retailers hide behind these technicalities to avoid disclosing treatments to consumers, Griffith says. That or they simply don’t know. “It’s not always made very obvious to the customer because it could be quite a turn off. It’s a resistance to disclose or not knowing themselves and part of that is because it can be so complicated and yet so common.”
To be sure, the supply chain for gemstones can be long and complex: miners often sell to “rough holders” who then sell to manufacturers who cut and polish. Gems are then sold onto wholesalers before they reach retail jewellers. Treatments can occur at any point in the process, making disclosure to the end consumer even harder, industry sources say.
Rubies that are not treated “are rare, and depending on the four C’s (same as diamonds), can reach record-breaking prices,” according to Gabriella Harvey, director of procurement and product services at Gemfields, one of the world’s largest coloured gemstone miners, which specialises in ethical sourcing. Heating, which improves colour, clarity and durability, allows for a broader customer base to enjoy coloured gemstone jewellery, she adds.
While suppliers and cutters may be increasingly transparent about it, jewellery retailers, particularly fashion jewellers, are lagging behind. “For many years, retail jewellers didn’t think about it. The miners would send to suppliers, suppliers would enhance them and because the retailer didn’t have the education to question what was coming from the suppliers, or the supplier felt it was traditional that these gems would need an enhancement of some kind,” the practice continued, according to Roskin from the International Colored Gemstone Association (ICA). “It never had an importance that it has today,” he adds. Today the ICA — with 750 members; mostly miners, cutters and gemstone suppliers — has a code of practice which includes mandatory disclosure of treatments.
Mandatory disclosure of the treatment of diamonds is required for certified members of the UK-based Responsible Jewellery Council. Coloured stones are soon to be included in the product disclosure, according to Anne Marie Fleury, director of standards and impacts. The body has just over 1,000 members, including luxury jewellers Van Cleef & Arpels, Cartier, Chopard, Boucheron and Bulgari. But that’s a drop in the ocean of the total industry and many lower-priced fashion jewellers are nowhere to be seen.