C. 1950 Vintage 2.40 ct. t.w. Amethyst Filigree Ring in 10kt Yellow Gold. Size 7

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.

AMETHYST: A natural variety of quartz, amethyst ranges in color from deep purple to pale lavender, and even to warm greens. Amethyst has been used during meditation to provide a sense of spiritual balance. Amethyst is the birthstone of February.

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.