This is a gorgeous estate 18K yellow gold carved shell cameo ring.  The ring is early 1960s and the woman has long neck and wavy hair, she looks like Jackie Kennedy!   Top of ring is 25mm x 18mm, about 1-1/8" long on the finger.   Inside marked 750, no other marks, ring made in Italy.  It is size 7.   Weighs 5.3 grams.  Very good pre-owned condition, no damage or problems.