C. 1990 Vintage 6.55 Carat Green Topaz Pendant Necklace with Diamond Accents in 10kt Yellow Gold. 18"

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.

CABLE: One of the most popular and classic of chain styles, created from interlocking oval links unvarying in size.

LOBSTER CLASP: named after the pinching style of the hook, this clasp is often shaped like a lobster's claw. Use your finger to work the lever to open the clasp.

DOUBLE: A bale that has two loops to slide a chain through.

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.

PEAR: Similar to the outline of a pear fruit, this is a round shape that comes to a point on one side.

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 H-I: Near-colorless