C. 1960 Vintage Oval Pink Coral Cabochon and .40 ct. t.w. Diamond Pin Pendant Necklace in 18kt Yellow Gold. 24"

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.

SPRINGRING CLASP: Invented in the early 1900s this diminutive device is highly effective. It's a hollow circular metal fastener with a spring opening. This keeps the clasp closed.

REVOLVER: A safety that conceals the point of a pin and keeps it in place with a revolving lever mechanism.

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 G-H: Near-colorless

Clarity VS1-VS2: Very slightly included. Inclusions are observed with effort under 10x magnification, but can be characterized as minor.

CORAL: This prized sea stone conjures up images of exotic oceans and faraway places. With shades ranging from soft muted pinks to vibrant bold reds, coral jewelry complements every skin complexion with a warm glow.

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.