Gem treatments have become increasingly sophisticated over time. In the early 1900’s, experiments were conducted with electromagnetic radiation and bombardment of gemstones with subatomic particles, which revealed that color change could be induced in some gem materials. Today, irradiation is routinely used to improve the color in a wide range of popular gemstones. Irradiation can occur in a nuclear reactor (neutron bombardment), an accelerator (electron bombardment), or by exposure to gamma rays in a cobalt irradiator. The treatment is often undetectable.
For some gemstones, the treatment is not permanent (stable). Exposing those gemstones to heat or strong light can cause the stone to lose the enhanced color. Examples of irradiated gemstones, whose color change is not stable, include orange sapphires and yellow sapphires. Colorless or light colored sapphire material can be irradiated to create vibrant orange or yellow sapphires; however, exposing the gemstone to bright light can cause the color to fade back to original in a matter of days. On the other hand, blue topaz is created from colorless or yellow topaz material through a two-step process. It is first irradiated and then heated to create a very desirable and stable blue gemstone. The color should not fade.
Some additional gemstones which include irradiation as part of their treatment and as far as we know under normal conditions the color change is stable include cultured pearls, yellow beryl and dark pink, red or purple tourmaline. Another irradiated gemstone whose color is not considered stable, is medium or dark green spodumene (from irradiating kunzite).
At 100 East and Sas E Gems Fine Jewelry, we disclose treatments our gemstones receive and use only irradiated gemstones whose treatment is considered stable (the color doesn’t fade) under normal conditions.
The Nuclear Regulatory Commission (NRC) is the main US government agency which governs the distribution of radioactive material, including irradiated gemstones. NRC regulations were written to safeguard public health and safety by setting concentration levels of radioactivity below which a U.S. entity can safely trade in gemstones. The NRC issues licenses to entities with a physical presence in the United States which allow the importation, possession, and distribution of irradiated gemstones. After the initial distribution by entities with the appropriate licenses, they can be freely traded.
Gemstones covered under NRC regulations are only those which might contain residual radioactivity sufficient to be detected by a Geiger Counter (either nuclear reactor or accelerator irradiated gemstones). The radioactivity is rarely high enough to be harmful, but it might be high enough for the gems to be illegal to possess. These include blue topaz and irradiated diamonds, beryl, and a small percentage of kunzite and red, pink or purple tourmaline. Gemstones treated with gamma rays do not become radioactive and are, therefore, not covered under these rules. These include irradiated pearls, yellow and orange sapphire, quartz, and the majority of kunzite and red, pink or purple tourmaline.
In summary, based on research reported by AGTA and Jeweler’s Vigilance Committee, the NRC has provided no indication that wearing irradiated gemstones is harmful or poses a health risk.