Any ideas of era, or if it was mourning jewelry or something like that?
This pin is not quite two inches long. It appears to be ivory or bone. The black parts appear to be painted (enamel?). The glimmery line through the black is tiny pieces of mother of pearl (some slivers are lost). The center would have been a cirlce of tiny silver dots, but about half are missing. I can't tell what the dots were made of.
It's not perfectly even -- in the pic of the back of the pin you can see the top edge is not parallel to the measuring tape on the left corner. Also there are these two filled-in holes on each side edge (you can see it in this same pic).
Another find from among FIL's storage unit -- this time in a china dish with a lid, filled with costume earrings for un-pierced ears.