Hi, I thought your vase may have been from here (see link) but I actually have one of these vases (my OH thinks it is hideous but to be honest, I rather like it

) and the base on mine is ground and polished clear. It is a well made vase, but as I think Christine said, just very slightly 'off' somehow (OH would say totally off, he really hates it). If I looked at it objectively, there are too many colours, too many patterns, the interior is red and is way to bright and the rim bit is too clunky. Having said all that everyone who comes in comments on it (gushingly positively I mean

) so it definitely has something about it.
I have no idea where these vases on this link come from, or are made but even with the flat ground polished base I do have a few doubts that it is Italy. However, I could be very wrong. oh and ps. I LIKE your vase (not totally the shape but I love the colours and patterns).
http://www.luxurylane.com/Hand-Blown-Abstract-Spiral-Art-Glass/M/B0028R3J7E.htmm