C. 1980 Vintage 5mm Nephrite Bead Station Necklace in 14kt Yellow Gold. 24"

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.

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.

ROPE: Chain links that are twisted or looped together in a pattern that creates a look similar to that of a rope.

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.

Nephrite: One of the two mineral species of jade composed of magnesium-rich amphibole (a silicate mineral). Popularly used in China, the decorative gemstone primarily comes in light to dark green, although it can be found in yellow to brown, white, black or gray. The color is often mottled.