C. 1980 Vintage .65 Carat Tanzanite Pendant Omega Necklace in 14kt Yellow Gold. 18"

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.

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.

TRILLION: A variety of the modified brilliant-cut, sometimes called "trilliant" or "trillian." Features a faceted triangular shape, sometimes with curved edges.