I bought a small lot of these last year, and never found out who made them.
Waisted vases of opal white base decorated with bubbles, coloured chips and insoluble powders, heavily cased in clear. Moulded base (except for one with a cut/polished base), cut/polished top rim. 160mm/70mm.
Foil label to the side of one, proclaiming its handmadeness, in French. Seller I bought them from was from France, and he said he thought the glass was French.
So I would assume French!
Any help gratefully received.