A pretty amazing little thing--one would think for holding very special pins, and not too many of them! I found a similar one listed as Napoleonic prisoner of war, French c. 1830s, but I don't actually think it is that; I would guess Victorian mid 19th c. Quite finely made whatever the case, with hand-stitching holding the two carved bone faces together, with a bit of stuffing covered in red fabric in between. 

2 5/8" l x 1" w x 7/16" d. Good condition, with no losses, just a little wear in a couple of spots to the fabric, documented (with lots of magnification) in photos, minor. I have not cleaned the face of the bone, but it might clean up a bit if desired.