C. 1970 Vintage 2.80 Carat Sapphire and 4.50 ct. t.w. Diamond Navette Ring in 18kt Yellow Gold. Size 6

18KT: Karat (abbreviated kt or K) is a unit that indicates the purity of gold in the metal. 18kt is 75% gold. In Europe, 18K 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.

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

CLARITY SI1-SI2: Slightly Included. Inclusions are noticeable under 10x magnification.

SAPPHIRE: A favorite gemstone of ancient priests and royalty, the sapphire radiates sophistication and grace. This prized gem comes in every hue of blue, plus the more unexpected shades of pink, yellow, green and orange, and is September's birthstone.

MARQUISE: An elliptical shape that comes to a point at the top and bottom. Sometimes referred to as a "navette."

BAGUETTE: An elongated rectangle step-cut. Typically used for smaller diamonds, but can be found in other gemstone as well.

Color Grade H-I: Near-colorless

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