This hyalite opal specimen not only will glow under an artificial UV lighting source, this particular source of hyalite opal will actually fluoresce in daylight, too! That is what makes this source(Zacatecas, Mexico) so unique. It looks best in diffused daylight, right outside of direct sunlight and it will have subtle green glow, while in indoor/home lighting, much of this opal is almost colorless. The intensity of daylight fluorescence will vary from piece to piece, but this particular piece has a moderate green glow in daylight.
This fluorescent response is due to the trace element of Uranium which this opal does contain. What this means is that these specimens are slightly radioactive, but according to a study done by Gem-A (The Gemmological Association of Great Britain), the relatively low levels of radiation (which vary from piece to piece) that are being emitted do not pose a health concern. That being said, to stay on the safe side, we still recommend taking proper precautions when handling any radioactive material, no matter what levels that are being emitted. This piece is pictured under a longwave UV flashlight (bright green glow) as well as in indoor/home lighting.
We consider this to be a Small Cabinet sized specimen (SMC). This beautiful mineral specimen is available today!