It's a very nice paperweight from the island of Murano, Italy, in the Venetian lagoon. I know that somewhere there is a series of pages that showcase Murano labels, but I don't know the link. I'm sure someone else does and will post it.
Identifying the label should help you know the factory or family of glassmakers on Murano that made the paperweight.
I really do like it. I like the blend of millefiori canes and colored latticino and ribbons. The weight was made sometime in the 1970s or 1980s, as I have something a touch similar, but not as colorful or as striking.