Before I researched it, to find out that it is a double salt cellar, I was thinking that it could be used for stamps - or some other type of desk accessory, because it is so hefty.

There are tiny, imperceptible "flea bites" only on the interior rim, where one might have tapped a spoon, but you can't really see them; only if you run your fingertip around this interior rim can you feel that they're there.  And they aren't very sharp, so I'm not entirely sure this isn't mostly a production anomaly.

Thoroughly clean.

4"L×3"W×1.5"H

Again, I might still rather use this on a desk. The glass quality is very nice; it catches the light. And I like the geometry of it.

Possibly antique.