This is a lovely vintage atomic floral burst style brooch featuring Japanese saltwater akoya cultured pearls. 

The pearls are 5.00-6.75mm round. They have fantastic luster with bright rosy pink overtones. They are set in a cluster around high polished and textured leaves. 

It is made of solid sterling silver and stamped "SILVER". Total length is 1 3/4 inch across. From Japan 1950's-1970's. 

All pearls are truly vintage and have only been lightly cleaned.