C. 1980 Vintage 4.00 Carat Smoky Quartz Ring with Diamond Accents in 14kt Yellow Gold. Size 5.5

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.

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.

QUARTZ: From the icy shimmer of rock crystal quartz to the delicate pink of rose quartz to the moody hues of smoky quartz, this gemstone offers something for everyone. Quartz, found in endless colors and varieties, is a popular choice for bracelets, necklaces, rings and earrings.

SQUARE: A symmetrical shape with four equal sides.

CUSHION: A gemstone that features a rounded square shape. The facet arrangement can be either a type of modified brilliant cut or a checkerboard pattern.

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.

BRILLIANT: A gemstone cut to enhance brilliance without sacrificing much carat weight. Typically has 58 facets.