This content was first published on IGR – Italian Gemological Review no. 17 in 2023. The information provided here is therefore current as of the original publication date.
Just before the Jaipur’s CIBJO Congress, the Coloured Stone Commission of the organization, led by Charles Abouchar, has released a comprehensive report on the state of colored stones. The report highlights a significant industry transformation, marked by a scarcity of supply that has led to notable price increases. This shortage is attributed to various factors, including the mining sector’s pandemic-related disruptions, export license challenges in Madagascar and Tanzania, China’s robust market demand post-lockdown, and heightened sales by prominent jewelry brands.
The interplay of reduced supply and heightened demand is anticipated to shape the market in the upcoming year, impacting both gemstone dealers and the broader jewelry sector. Simultaneously, the industry contends with issues related to the detection of treatment. Various treatments, some previously unnoticed, present challenges in terms of detection and disclosure. While the detection of low-temperature heating in gemstones like rubies and corundums is well-researched, inconsistencies persist across different laboratory detection methodologies.
The irradiation of gemstones, a practice known for years, continues to face issues of proper disclosure mostly because it is undetectable. Tourmalines, morganites, kunzites and other irradiated stones are frequently sold without any indication of their treatments. Irradiation of corundums is unstable. Furthermore, the common practice of oiling gemstones with fractures often lacks consistent reporting.
In response to these challenges, the Coloured Stones Commission has revised the CIBJO Coloured Stones Blue Book, placing a strong emphasis on the necessity of transparency and disclosure and has clarified that all gemstone treatments must be disclosed to the customer as step in the Clause 4.2.5.1 “Informing the Customer”: «It is in the best interest and responsibility of the trade for consumers to be fully informed with regards to any treatments applied to gemstones. Treatments may impact a gemstone value, and are often not permanent or may require special care; the seller shall therefore inform the purchaser about the treatment and any special care requirements». For the purpose of the implementation of correct terminology CIBJO’s President announced the launch of an academy for educational services.
| CODE | TYPE OF TREATMENT |
DESCRIPTION |
| W | Surface Waxing: Gemstones treated on the surface or just below the surface with a colourless agent such as wax and/or oil that acts or serves the same purpose as wax. | Waxed |
| O | Fissure-Filling with Oil: Gemstones that have fissures or very narrow openings filled with colourless to near-colourless agents such as oil. | Fissure filled with oil |
| RES | Fissure-Filling with Resin or Other Polymers: Gemstones that have fissures or very narrow openings filled with colourless to near-colourless agents such as resin, polymer or any similar substances, other than glass. |
Fissure filled with resin |
| F | Filling of Fissures, Fractures and/or Cavities with Glass and Other Solidified Substances: Gemstones treated by the filling of open fissures, fractures and or cavities with substances such as glass, plastic or similar substances. | Fracture-filled or glass-filled |
| H | Heating: Gemstones treated by a thermal process in a furnace, kiln or other heating apparatus. | Heated |
| HP | Heat with Pressure: Gemstones treated by the use of heat with pressure to effect desired alterations of colour, clarity. |
Heated with pressure |
| FAH | Flux-Assisted Healing: Any corundum that shows indications of having undergone heat treatment, and a degree of healing along previous fractures, that contain residues such as glass from the heating process. | Heated in flux |
| B | Bleaching: Gemstones treated by bleaching to remove or alter a colour by means of chemical or physical agents or light. |
Bleached |
| R | Artificial Irradiation: Gemstones treated to change their colour by artificial irradiation. |
Artificially irradiated |
| U | Diffusion Treatment: Gemstones with a colour treated and/or an optical phenomenon created, by diffusion of chemical elements from an external source, with the exception of hydrogen and oxygen. |
Diffusion treated |
| D | Dyeing: Gemstones with a colour altered by dyes or other colouring agents or stones darkened by the “sugar/acid” process. |
Dyed |
| I | Impregnating: Gemstones treated by impregnation with plastic or similar substances. This clause does not include the bonding of powdered materials, which are artificial products. |
Impregnated |
| C | Coating: Gemstones treated by coating with a layer of a substance spread over the surface, or part of the surface, such as lacquering, enamelling, inking or foiling for protection, colouration or deception. |
Coated |
Tab. 1 – Appropriate disclosure of treatments in gemstones according to the CIBJO Special Report 2023 of the Coloured Stone Commission.
Gem News published on IGR – Italian Gemological Review #17, Autumn 2023
