Gem: Hyalite Opal
Weight: 5.15 ct.
Dimensions: 18 x 13.3 x 4.3 mm
Clarity: SI 2
Origin: Zacatecas, Mexico
Treatments: None
Comments:
This very cool gemstone is daylight fluorescent to a nice light yellow color, but the REAL show starts under black light.
Trace uranium content (as safe, or safer than background radiation from granite countertops) causes the unbelievable slimer-green coloration, exactly the same way as antique uranium glass.
There are some internal features inside the gem - which are mostly leftover spaces between layers of water-deposited silica and trace uranium. However, the very small dark spots are purple fluorite cubes. They are there, but I wouldn't say that any of them are noticeable by eye.
This one is fit for an impressive piece of custom jewelry, or a simple pendant-with-bail. It's a little too soft to be a ring, though.