Kent...It's about 1 1/2 inches across and 3/4 inch tall. I dug it out of a box of bottles that my dad had collected so the age is totally unknown. It does look like a stopper of some sort. I'm pretty close to Smith Glass, Anchor glass, and Bryce glass factories. It could have come from one of them.
AT first I thought it might be a glass thngie from an old percolator, but it isn't hollow, is it? Then I thought it might be some type of older insulator.