The ICA’s reputation has been recognized internationally more than ever due to the fact that ethical trade practices have become a new fundamental value of a sustainable business model. The time is right to engrave our history even more deeply into the core of the gemstone sector by leading the global industry of gems and jewellery with proper disclosure, by indicating Common Disclosure Code (CDC) on every sales document produced, as suggested by the ICA.

Disclosure is both the seller and buyer’s responsibility. It is the buyer’s responsibility to collect the correct information from the seller, in order to provide full disclosure on their inventory.

Disclosure is the fundamental and most important step of ethical trade. This is vitally important in order to achieve two main goals of the ICA, which are: “working with organizations to standardize rules and nomenclature” and “to maintain and perpetuate ethical standards among members.”

With updated treatment information, use of disclosure codes becomes the most reliable means of communicating accurate information concerning a gemstone.

The ICA has recently adopted the AGTA's source disclosures.


N Natural: No modification (or currently has no known modification process).

B Bleaching: The use of heat, light and/or other agents to lighten or remove a gemstone’s color.

C Coating: The use of such surface enhancements as lacquering, enameling, inking, foiling or sputtering of
films to improve appearance, provide color or add other special effects.

D Dyeing: The introduction of coloring matter into a gemstone to give it new color, intensify present color
or improve color uniformity.

F Filling: The filling of surface-breaking cavities or fissures with colorless glass, plastic, solidified borax or similar
substances. This process may improve durability and/or appearance, and/or to add weight.

H Heating: The use of heat to effect desired alteration of color, clarity and/or phenomena.
If residue of foreign substances in open fissures is visible under properly illuminated 10X magnification, H F
should be used.

HP Heating and Pressure: The use of heat and pressure combined to effect desired alterations of color, clarity
and/or phenomena.

I Impregnation: The impregnation of a porous gemstone with a colorless agent (usually plastic) to improve
durability and appearance.

L Lasering: The use of a laser and chemicals to reach and alter inclusions in gemstones,
usually diamonds.

O Oiling/Resin Infusion: The filling of surface-breaking fissures with colorless oil, wax, resin or other colorless
substances, except glass or plastic, to improve the gemstone’s appearance.

R Irradiation: The use of neutrons, gamma rays or beta particles (high energy electrons) to alter a gemstone’s
color. The irradiation may be followed by a heating process.

U Diffusion: The use of chemicals in conjunction with high temperatures to produce ARTIFICIAL color
change and/or asterism-producing inclusions.

About Us

The ICA is a worldwide body specifically created to benefit the global colored gemstone industry by advancing and promoting the knowledge and appreciation of colored gemstones.
New York Office: 31 West 47th St., Suite 1103, New York, NY 10036
+1 (212) 620-0900
ica (at)
Hong Kong Office: Unit 311B, 3rd Floor, Heng Ngai Jewelry Centre No. 4 Hok Yuen Street East, Hung Hom, Kowloon, Hong Kong
+852 2365-9318
ica (at)

ICA Newsletter