C. 1950 Vintage 2.50 Carat Aquamarine Marquise Ring in 14kt White Gold. Size 4.5

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.

WHITE GOLD: Gold is a precious metal which is naturally quite soft. To give it a white color and increase its strength, gold is alloyed with white metals, such as silver and/or palladium, and often plated with rhodium. The purity of the metal is indicated by a unit called a "karat," with 24kt having the highest percentage of natural gold.

FILIGREE: a term for gold or silver wire that has been twisted into patterns and soldered in place. Modern stamping techniques can replicate the decorative appeal of this ancient artform.

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.

MARQUISE: An elliptical shape that comes to a point at the top and bottom. Sometimes referred to as a "navette."