This is a unique blue/gray baroque Japanese akoya saltwater cultured pearl & sterling silver grape pendant.

The pearls measure 5.25-5.75mm and are a medium blue/gray color with light pink overtones. They are a baroque shape. 

It is made of solid sterling silver and features a swirling vine and engraved grape leaf details. Total pendant drop is 1 1/8 inch. Not stamped. From Japan 1940's-1980's. 

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