Preciosa Glass Cab with 'bubble' detail in Helio Blue.
Helio Blue looks blue/purple dead on, but changes to fuchsias, red, and yellows depending on how you look at it.
It looks mostly clear from the side.
The back is flat with raised flat nubs, as shown, and is silver foil-backed.
There are no holes.
Made from Czech Glass by Preciosa.
This piece measures 25x18mm.
You will receive one cabochon.