Measuring 2&7/8 inch long, this is a very old brooch that is made of silver metal. It has no markings. It was tarnished when I purchased it. I quickly rubber with my silver cleaning cloth, and quite a bit of the tarnish was removed. I don't believe it's sterling, but rather a nickle, or German silver. Because of the simple, open c clasp on the back, I would date it to the 1910's-20's.
Please note that photos are enlarged to show detail. I currently have several pieces of vintage, costume jewelry in my shop, and am happy to combine shipping. To see them all, type the word, "jewelry" in the California Girls search box at the top of this page