This is a vintage/used costume jewelry pin.
Signed "1928" on the back.
Metal is silver-tone and center stone is black.
Size is about 1 7/8 inches long.
 

Good used/vintage condition; might need some light cleaning/polishing and have some normal age ware. 

Because my items are vintage/used they may have some signs of use/wear and/or be in need of some cleaning or polishing. I have not tried to clean or do anything to the piece.