This is a lovely mid-century Japanese akoya saltwater cultured pearl tie bar.

The pearl is 7.50mm round. It has mirror like luster with bright rosy overtones. 

The setting is made of solid silver. Stamped "SILVER" which is an older mark for sterling. The metal has a well executed crosshatch pattern to give it a unique texture. Total length is 2 inches. 

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