I recently was lucky enough to find this exquisite piece of alexandrite glass, and cannot find good information on the net or in my limited library. It's signed "Moser Karlsbad Alexandrit." It measures 20.5 cm (8 1/4"). Would this be from the Art Nouveau or Art Deco period, what is its approximate age and is there a name for the particular line in which it was produced? Any info would be appreciated.