They are lampworked. A propane and O2 mix. They are soft glass not Boro. I use a marble mold for the back then blow out the dots. The flame is almost as addictive as sawdust.
Humm, bigger pics. Hopefully these are bigger. They are about the size of a 50cent piece. I have made them as refrigerator magnets, necklaces, earings and guardians of my pens.