C. 1980 Vintage Opal Ring with .95 ct. t.w. Diamonds and .20 ct. t.w. Sapphire in 18kt Yellow Gold. Size 7

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.

OPAL: With an iridescent luster that can reveal a beautiful kaleidoscope of color, the opal has inspired many myths and legends. A white opal with swirls of soft pastel shades is popular for jewelry, but opals also come in black and blue. Opal is the gemstone for October birthdays.

OVAL: An elliptical shape that resembles an egg.

CABOCHON: A style of cutting gemstones to achieve a smooth, domed surface with an absence of facets.

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.

Color Grade F-G: Colorless to near-colorless

Clarity VS2: Very slightly included. Inclusions are observed with effort under 10x magnification, but can be characterized as minor.

CLARITY SI1: 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.