Possibly not Pompeian in view of the snapped/slightly fire polished pontil mark. Texture of bubbles can be felt on the inside, and plenty of striations running around the glass - top half in particular, and there is a matt wear ring on base, so get the impression could be first half C20, when this shape was not uncommon - especially the '20's and '30's
Difference of c. 1/8" in height on opposing sides, and very uneven thickness to base - height is something like 5.7/8" - 150mm, and dull clunk when struck. Top rim is rounded and smooth.
Appreciate these bubbled pieces can be difficult, but just wondered if anyone might have any thoughts or want to take a stab at origin and date. Thanks for looking.