C. 1990 Vintage 52.50 ct. t.w. Aquamarine Bead Station Necklace in 14kt Yellow Gold. 18.5"

14KT: Karat (abbreviated kt or K) is a unit that indicates the purity of gold in the metal. 14kt is 58.33% gold. In the United States, 14K 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.

ROPE: Chain links that are twisted or looped together in a pattern that creates a look similar to that of a rope.

SPRINGRING CLASP: Invented in the early 1900s this diminutive device is highly effective. It's a hollow circular metal fastener with a spring opening. This keeps the clasp closed.

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.