As technology advances, it seems that more and more things are being subjected to irradiation. It has many uses. Mail gets irradiated to kill potential biohazards; medical supplies get irradiated for sterilization; food gets irradiated to increase its shelf life.
Even gemstones get irradiated.
In the wide world of the jewelry industry, it is no secret that gemstone treatments are prevalent. It is what it is. As long as proper disclosure is made, a greater supply of beautiful gemstones is brought to the market because of gem enhancement techniques. Next to heating, irradiation is probably the most common gemstone treatment out there.
Quartz, pearls, tourmaline, diamonds, spodumene, topaz, and beryl are all routinely irradiated to improve their colors, or even alter them entirely. In fact, natural blue topaz has never been known to achieve the deep blues of irradiated topaz. Natural blue topaz is also so rare that you’ll likely never even see it in a jewelry store.
The biggest question, of course, is: Are irradiated gemstones safe to wear?
History of Irradiation Treatment
Scientists have been experimenting with irradiating gemstones for almost as long as they’ve had access to radioactive materials with which to conduct their experiments.
Shortly after the turn of the 20th Century, Sir William Crookes packed diamonds in radium boride salts, and after over a year, noted that the diamonds had turned green. It was only a skin deep change, however, and it also left lasting harmful radioactivity upon the diamonds, making them useless for anything other than nightlights for Superman.
But we’ve come a long way since then. There are three primary methods used for irradiating gems nowadays, with each being more and more costly and time-consuming than the previous method.
The first method is gamma radiation exposure, usually conducted with proximity to the radioactive isotope Cobalt-60. This method leaves little to no residual radiation, and has a minimal effect on most gemstones.
The second method is exposure to electrons in a linear accelerator (shortened to “linac treatment”). This process also leaves very little residual irradiation and has a much more pronounced effect on most of the gems subjected to it.
Most of the irradiated gems on the market in the United States are treated by one of these first two methods.
The third method is neutron bombardment in a nuclear reactor. This method produces markedly different shades of color, if not different colors altogether, by significantly altering the elemental impurities in the gems being irradiated.
A “cooling off” period is required to make certain the residual radioactivity has decayed to safe handling levels. Depending on the elements altered and the isotopes created, that can be a matter of weeks or a stretch of years. Trace chemical composition of the same mineral varies from deposit to deposit, and so how material from each source responds can be a crapshoot.
Due to the unhealthy levels of residual radiation created by neutron irradiation, material subjected to this method is heavily regulated in the US.
Irradiated Gemstone Stability
Gemstones treated by irradiation that reach the retail market have, for the most part, stable color. A notable exception to that rule is spodumene, one variety of which, kunzite, is notorious for its color fading whether it has been treated or not. Spodumene that has been irradiated to a green color may also fade, but not all specimens do so.
But fancy color diamonds, golden beryl, blue topaz, and red tourmaline, etc. are all known to have stable coloration. Reverting their colors would require the same amount of energy used to create their colors in the first place; and most people don’t spend much time basking in the glow of Cobalt-60…I hope.
Irradiated Gemstone Pricing
Like most gems subjected to enhancements, irradiated stones are usually less costly than their natural counterparts of comparable color quality. The best example is irradiated diamonds, which are much less costly than natural fancy color diamonds.
Irradiation does have a corner on the market for some things, though. There are particular shades of irradiated blue and blue-green diamonds that do not even exist in nature. The same is true for virtually all blue topaz and certain intensities of golden beryl, yet they are wildly popular across the market. Were it not for irradiation enhancement, these would not even be available to be appreciated.
The advents of science really are fascinating, and in the case of jewelry, they tend to be rather beautiful is well.
What are your thoughts on purchasing or owning irradiated gemstones?