C. 1930 Vintage Cultured Mabe Pearl and .75 ct. t.w. Diamond Cocktail Ring in 18kt Yellow Gold. Size 5.75

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.

MABE PEARLS: With their big, showy dome, mabe pearls offer all the glamour of South Sea pearls at a much more affordable price. Cultivated with a flat back, mabe pearls are a favorite for fine earrings, rings and pendants.

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.

ROSE-CUT: An antique gemstone cut dating back to the 1500s, with a flat back and a faceted top.

Color Grade H-I: Near-colorless

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