Fairy Glass, a magical object left behind?
If I had to guess, I would say they look like they have been made with recycled glass ( thats why it is a bit cloudy ) and a secret mixture of german glass glitter and maybe fairy made pigments?  I can also tell its been soldered using a lead free, jewelry grade solder. 
Every one is one of a kind! 
 
These are a bit on the larger side and only slightly heavy.