This is a stunning classic Japanese akoya saltwater cultured pearl mid-century modern necklace. 

If features a single, highly lustrous, pearl measuring 5.75mm. It is nice quality  and has light rosy pink overtones. 

It is in solid white gold and is stamped "14K" on the pendant and chain. Total drop is 3/4 inch. Chain is 18 inches. 

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