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."

WIRE: sometimes called "shepherd's hooks" or "fishhooks," earwires are a thin, hook-shaped earring backs. They thread onto the ear and can sometimes be squeezed into place or held on with a rubber clutch.

QUARTZ: From the icy shimmer of rock crystal quartz to the delicate pink of rose quartz to the moody hues of smoky quartz, this gemstone offers something for everyone. Quartz, found in endless colors and varieties, is a popular choice for bracelets, necklaces, rings and earrings.

OVAL: An elliptical shape that resembles an egg.

MOONSTONE: named for the white reflection that mimics the reflection of moonshine. Typically polished and featuring a cabochon cut, moonstone's light-catching shimmer is perfect for fine jewelry. In Europe, moonstone is the birthstone for June.

OPAL: With an iridescent luster that can reveal a beautiful kaleidoscope of color, the opal has inspired many myths and legends. A white opal with swirls of soft pastel shades is popular for jewelry, but opals also come in black and blue. Opal is the gemstone for October birthdays.