I had no idea ashtrays were so collectible. It came from my mother's eclectic antique collection. I assume my ashtray isn't rare cause a quick search found one for $20. Although mine is made in Canada.
Here's a piece from my Native collection. A half of bowl of a pipe - used. Grid is 1 cm. I found it (and other stone tools etc) while following a sod cutter in the summer of '73. Seneca tribe (Iroquois) & pre-1600. You can see a groove where it had a hollow wooden stem.
Ian