This is a lovely retro Japanese akoya saltwater cultured pearl modernist pendant necklace. 

The pearl measures 7.00mm. It is a white/cream color with good luster and light rosy overtones. 

It is made of solid sterling silver and has a unique swirling square design. Pendant measures 7/8 inch and is stamped "SILVER" which is an older mark for sterling. It comes with an 17 inch chain which is also stamped "SILVER". From 1950's-1980's.

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