C. 1980 Vintage .25 Carat Sapphire Ring with Diamond Accents in 10kt Yellow Gold. Size 5

10KT: Karat (abbreviated kt or K) is a unit that indicates the purity of gold in the metal. 10kt is 41.67% gold.

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.

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.

OVAL: An elliptical shape that resembles an egg.

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.

SINGLE-CUT: A gemstone cutting technique that dates back to the 1300s. Still used today, the single-cut usually features 18 facets that go in one direction without crossing each other.

Color Grade I-J: Near-colorless

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