This is an early 20th c lucky horse shoe & a bird, for happiness. The bars of the shoe are pointing downwards for good luck to wash over the recipient.
It is sterling and the bird has a glittering green stone eye which is probably a paste stone. Brooches of this kind were often given to brides as a token for a happy marriage. It is 1 1/2” x 1 1/4” and closes with a simple C clasp.