This is a retro atomic era Japanese akoya saltwater cultured pearl snowflake burst brooch.

The pearls are 3.25-5.50mm round. They have fantastic luster with bright rosy pink overtones. 

It is made of solid sterling silver. It has an atomic burst design with a clean high polished style. It is stamped "STERLING". It measures 1 1/8 inches long. Can be worn as a brooch but also has a pendant loop. From Japan 1950's-1960's. 

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