C. 1980 Vintage 21.00 Carat Citrine and Simulated Tanzanite Bead Necklace in 14kt Yellow Gold. 17.25"

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.

BALL: A round, bead-like clasp. Sometimes adorned with gemstones or texturing, ball clasps provide a decorative closure that does not take away from the design of a necklace or bracelet.

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.

OVAL: An elliptical shape that resembles an egg.

TANZANITE: Found in the 1960's, tanzanite is new and rare discovery that captures magnificent shades of purple, violet and blue. Its crystal structure allows light to enter the stone and divide into two or three sectors which enhances the intensity of color. Tanzanite is an alternate for December birthstones.

FACETED BEAD: A stone with a drilled hole and a faceted surface. Strung together to decorate bracelets, necklaces, and earrings.