Inkwells
Art Nouveau inkwells tend to be the ornate cast metal inkwells. Depending on your taste and budget you can find brass, bronze, copper, silver and others. You can also select by country of manufacturer such as England or Germany.
It's hard to remember that at one point there was as least one inkwell on every desk in the wold. Inkwells were manufactured for every student desk and expensive ones were made for executive gifts.
The Art Nouveau inkwells are interesting because the form could run wild and still retain the functionality. Even if you are not especially interested in Art Nouveu, it is worth a look just to see how many ways metal can be cast.