Dating from the late 1800's and measuring 1 & 1/16" NBS Medium, this is a molded black glass button. It features a castle and bridge along with trees and lots of other detail. It is backmarked "PATENT APPD. FOR" and has a brass plate & loop shank. In good condition, although it has a shallow chip on the rim at 1 o'clock. $8

Click on the pictures to enlarge. I've tried to lighten it enough for you to see it, but the scan isn't good.