It reminds me more of the Cenedese pieces that I've seen, except that those are usually signed. I haven't seen any Barovier like this so I'd have the same question as Anita.
David
P.S. On thinking about it, why not Seguso V d'A? The Cenedese scavo pieces tend to have those dirty blackish patches, whereas Seguso were purer colour--and unsigned generally.