C. 1970 Vintage 51.50 Carat Citrine Ring in 14kt Yellow Gold. Size 6.25

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.

CITRINE: A member of the quartz family, citrine symbolizes cheerfulness and prosperity. Its name is derived from the French word citron meaning lemon. This sunny stone comes in colors from lemon yellow to amber brown, with its coloring agent attributed to iron. Citrine is the birthstone for November.

EMERALD: the birthstone of May, and from the beryl mineral family, the emerald has been a prized possession of royalty since ancient times and a good quality emerald can be as or even more expensive than a fine diamond of the same carat. Emeralds are considered the traditional gift for the 55th wedding anniversary.