C. 1980 Vintage .10 Carat Diamond Pendant 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.

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.

Diamond: The hardest and most brilliant of all gemstones, a diamond can make the heart race with its pure and fiery spark. An ancient symbol of love, a diamond is the preferred gemstone for tokens of affection, such as rings, earrings, necklaces and bracelets. Diamond is the birthstone for April.