This is a really cute and unusual brooch in sterling silver. It is in the form of a dragonfly and it has a very unusual catch. It is called a sweater pin. To attach the pin you squeeze the wings and the two sharp pins on the back open. It is marked Sterling and is probably Mexican in origin.
It measures 1 7/8 inches by about 2 1/8 inches and it is in very good condition. There is a slight bend to one wing that does not affect the pin mechanism and isn't very obvious.