This is beautiful signed Uncas Sterling Silver pin that has sparkling marcasites and enameling. According to the Brunalti book mentioned again below, the piun was designed by Nicholas Barbieri who worked for Uncas fro 1937 until 1948. This item was patented in 1938 with Pat. No.108229. The brooch is 1 5/8" in diameter, made of heavy sterling with enameling on the palms and exotic peacock birds. All the marcasites are original and accent the palm tres and are set all the way around the edge of the brooch. It is in excellent condition with no chips or problems with the enamel or marcasites. As I noted above, this piece appears in the Brunialti's book,"A Tribute to America", pp. 215-216along with information about the company and designer. It is definitely a collector's piece as well as a beautiful brooch to wear.
If you look at the picture of the back the Uncas trademark of a U with and arrow going through it is there.