Gem: Hyalite Opal
Weight: 2.84 ctw.
Dimensions: 6.35 x 6.55, and 8.6 x 5.5 mm
Clarity: SI, but very gemmy
Origin: Zacatecas, Mexico
Treatments: None
Comments:
This material is RAD! I have always loved it. This type of hyalite opal has what's called dayglow fluorescence, which means that this gem is yellow in daylight due to intense fluorescent reactivity with any and all UV light.
Now, if you actually put these gems UNDER a UV light, i.e. a blacklight, you will see, the color goes nuclear! literally! the overly excited (glowing) aspect of the stone is due to diffused radioactive uranium atoms trapped between the crystal structure, deposited slowly by water over time.
The amount of radiation in this type of material is extremely low, like less than granite kitchen countertops. Uranium glass actually works on a similar principle, and is similarly safe to have in the home.
These are high-dome cushion cabs. They have a few inclusions, but are primarily extremely gemmy, all in all.