Hyalite opal is an unusual gem that is beautiful in its own way. Many contain trace amounts of uranium which enable the gem to glow under a UV light. I have a small piece in my own collection that I scored at a gem show in Atlanta back in 2019.
Recently, I had a customer request a faceted gem wrapped into a ring. The stone wound up being way too small and I made the wrap focus on securing the gem so it wouldn’t fall. The result is best visible under a UV light as you can see in the image above.
In the video below, I show if the gem before and after the wrap. I study it under a jeweler’s loup and used the Nitecore UV longwave light to show how it glows. However, this particular stone glowed faintly in the daylight–which is not that common. I didn’t have a Geiger counter so was unable to test and see if it emitted any cpm.
CPM means counts per minute and measures radioactivity. It’s the number of atoms in a given quality of radioactive material that are detected to have decayed in one minute.
According to this website, they’ve tested a few radioactive minerals including Hyalite—they got theirs from the same mine my piece came from (Chalk Mountain Mine, Spruce Pine, NC) and the results showed that their Hyalite emitted a radioactivity level of 300 cpm.
One thing I will say that I learned from this experience is that I won’t be working with the super tiny gems. I have fat fingers and it was a miracle that I was able to wrap this one.
The gem in the photo below is the one I wrapped and this photo is magnified 30 times.
The photos below are the final ring. The first one is without the UV light. It was also taken outside in daylight. You can see the stone’s natural greenish tint.
After the UV light is applied, the gem glows this beautiful bright apple green.
Although uranium is pretty deadly, the amounts in these opals are very low and from what I can tell (researching online) is that it’s pretty safe to wear as jewelry. I’ve had my hyalite for over a year and I’m perfectly fine.