C. 1990 Vintage .45 Carat Princess-Cut Diamond Solitaire Engagement Ring in 14kt Yellow Gold. Size 6

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.

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.

SQUARE: A symmetrical shape with four equal sides.

PRINCESS: A multifaceted gemstone cut that has a square or rectangular shape with a facet arrangement that yields a similar level of brilliance to the round brilliant-cut. The princess-cut is known for the distinct "x" shape it renders while looking through the table.

CLARITY SI2: Slightly Included. Inclusions are noticeable under 10x magnification.