C. 1990 Vintage 2.55 Carat Aquamarine and .25 ct. t.w. Diamond Pendant Necklace in 18kt Yellow Gold. 18"

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.

CABLE: One of the most popular and classic of chain styles, created from interlocking oval links unvarying in size.

LOBSTER CLASP: named after the pinching style of the hook, this clasp is often shaped like a lobster's claw. Use your finger to work the lever to open the clasp.

AQUAMARINE: The birthstone of March, harbinger of spring, aquamarine's powers of revelation are legendary. Usually cut as a brilliant or a step cut, and a member of the beryl family, aquamarine can be found in a range of pale blue hues and aqua green colors.

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.

BRILLIANT: A gemstone cut to enhance brilliance without sacrificing much carat weight. Typically has 58 facets.

Color Grade G-H: Near-colorless

Clarity VS2: Very slightly included. Inclusions are observed with effort under 10x magnification, but can be characterized as minor.

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