9.75 Carat Pear-Shaped Ruby and .16 ct. t.w. White Topaz Pendant Necklace in 18kt Gold Over Sterling. 18"

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.

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."

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.

RUBY: A bold fiery stone, the ruby is a symbol of wealth, vitality and love. When cut and polished, the ruby's high luster is as dazzling as a diamond's. Ruby jewelry makes the perfect gift for loved ones and is the birthstone for July.

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

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.