Thank you Chopin-Liszt & catshome. It's difficult to describe (it would be so much easier if you could hold it:) the outside is odd. I can't tell what's air or frit. It has a look like it's been treated with acid! I don't know if that's ever done to glass? Can glass crizzle with age? I've never heard of that,lol. I can't see any straight lines, maybe some following the contours of the glass but I think it's just random.
No markings on the metalwork I can find either. It maybe brass but I'm not sure, sorry, not much help am i, lol. I wondered if it could be ormolu?