A Roman gold snake ring, circa 1st century BC-1st century ADEstimation: USD 10,000 - 15,000Photo Christie's Image Ltd 2015

Formed from a sheet strap, wound into a three-coil spiral, the tail sharply curled back and looped, the neck and head turned out forming a backwards S, with stippled and incised details indicating the scales - 1½ in. (3.8 cm.) long; ring size 6

PROVENANCEAcquired by the family of the current owner, Geneva, prior to 1989; thence by descent.

Christie's. Ancient Jewelry sale - Online auctions December 1 -10.