C. 1950 Vintage Agate Cameo Ring with .45 ct. t.w. Diamonds in 18kt Yellow Gold. Size 6

18KT: Karat (abbreviated kt or K) is a unit that indicates the purity of gold in the metal. 18kt is 75% gold. In Europe, 18K yellow gold is most favored and used in jewelry.

YELLOW GOLD: Gold is a precious metal with a natural yellow color. It is quite soft and often alloyed with other metals to increase its strength. The purity of the metal is indicated by a unit called a "karat," with 24kt having the highest percentage of natural gold.

AGATE: a variety of chalcedony, agate covers a rainbow spectrum of colors from black and gray to brown, pink, blue and yellow. Agate can be textured and exhibit a variegated layered stripe effect, which makes it a wonderful stone for carved cameos and beaded necklaces and bracelets.

OVAL: An elliptical shape that resembles an egg.

Diamond: The hardest and most brilliant of all gemstones, a diamond can make the heart race with its pure and fiery spark. An ancient symbol of love, a diamond is the preferred gemstone for tokens of affection, such as rings, earrings, necklaces and bracelets. Diamond is the birthstone for April.

SINGLE-CUT: A gemstone cutting technique that dates back to the 1300s. Still used today, the single-cut usually features 18 facets that go in one direction without crossing each other.

Color Grade H-I: Near-colorless

CLARITY SI1-SI2: Slightly Included. Inclusions are noticeable under 10x magnification.