C. 1990 Vintage David Yurman 4.50 ct. t.w. Swiss Blue Topaz and .40 ct. t.w. Amethyst Earrings in Sterling Silver and 14kt Yellow Gold

STERLING SILVER: Also known as "Standard Silver," sterling silver is silver alloyed with other metals to increase the hardness and durability. Generally, sterling is 92.5% silver and 7.5% other metals. Some sterling silver jewelry is plated with 14kt-18kt gold and referred to as "vermeil," or "gold over sterling."

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.

CLIP/POST: An earring with a post insert and a clip mechanism to hold it in place. The post can be removed by a jeweler to convert the earrings to clip-on.

TOPAZ: Available in a stunning selection of shades, the topaz's sky blue hue is one of the most popular colors for jewelry designs. Once thought to offer protection, today topaz is favored for its durability and affordability. Yellow topaz is the birthstone for November while blue topaz is for December.

CHECKERBOARD: A technique that creates a contrast of dark and light when light hits the pattern of square or diamond-shaped facets.

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.

SQUARE: A symmetrical shape with four equal sides.