Fluorescent Diamonds

I was browsing the Gemological Institute of America’s blog when I came upon a post about fluorescent diamonds. My first gem I had that glows under UV light is Hyalite which gets its glow from trace amounts of uranium. Many minerals glow different colors in UV light, but I didn’t know that diamonds did. Now I do and GIA breaks down some myths around these glowing diamonds.

One myth is that they only glow blue, but the can fluoresce in a myriad of colors. Orange, yellow, red, white and green. Atomic structure is key to this phenomenon yet blue is the most common color of diamond fluorescence.


GIA is known for its 4Cs in diamond grading. They stand for color, clarity, cut and carat weight. Diamond fluorescence isn’t given a grade like the 4C’s however there are intensity gradings. None, faint, medium, strong and very strong.

Seeing that about fluorescent diamonds got me curios about some of the diamond jewelry I still have in my online store. I put it to the test with my UV black light, but as you can see, it doesn’t fluoresce. 



I got inspired by the blog post to try it on one of my jewelry pieces that is currently for sale in my online store. The piece is a Moldavite (bottom) and raw white diamond (top) that I wrapped in Sterling Silver that is starting to tarnish.

I have the UV black light that was given to me by a dealer back in May and I use it to on the hyalite. I used it as you can see in the video to the left, on the pendant and it did not fluoresce.

However, the diamond did reflect the light from the black light as you can see in the video. Its pretty cool that a raw, uncut, unpolished diamond did that.

GIA points out also that fluorescence in gems do not add or take away the value. If the Diamond were to have glowed green I think it would have been fun! It would match the hyalite.

Note: All images from Gemological Institute of America.