C. 1999 Vintage 1.4mm 18kt Yellow Gold and .25 Carat Diamond Omega Pendant Necklace with British Hallmark. 16"

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.

OMEGA: A notably shiny chain formed by flat plates crimped together over a mesh interior. The semi-rigid structure gives it a unique look, perfect to wear as is or pair with a slide pendant.

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.

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.

Clarity VS1: Very slightly included. Inclusions are observed with effort under 10x magnification, but can be characterized as minor.