This is a stunning vintage Japanese saltwater cultured pearl ring by Fuji Pearl. They were a high quality designer that went out of business around the 1950's. 

The pearl is high quality and measures about 7.50mm. It has great luster and is surrounded by butterfly details. 

It is set in solid sterling silver. It is stamped "SILVER" which is an older mark for sterling, great workmanship. US size 8. Comes in the original box which is in good shape, but missing some of the original gold leaf on the name. 

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