Antique gold brooch made in france

by Dee
(Perth)

Hi I wanted to ask about a piece of jewelry in our family; it's a gold cylinder that slides apart slightly to reveal a gold tooth pick, we definitely know that it came from France, it is a brooch and it has a black stone set on top.

the mystery is, that this piece has no hallmark what so ever on this unusal item why would it not have a hall mark; I have checked out the entire piece from top to bottom and there is nothing please help