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.

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.

OVAL: An elliptical shape that resembles an egg.

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 H-I: Near-colorless

CLARITY SI1-SI2: Slightly Included. Inclusions are noticeable under 10x magnification.

OLD MINE CUT: An antique gemstone cut dating back to the 1700s. Features a rounded square silhouette similar to the modern cushion-cut, but conforms to the shape of the rough gemstone in order to preserve the weight. The culet is usually large enough to be easily seen through the table of the diamond.

CLARITY SI2: Slightly Included. Inclusions are noticeable under 10x magnification.

GLASS: A delicate, translucent to transparent noncrystalline material made by fusing sand with other materials , such as soda and lime, and then cooling it quickly. Glass is used in anything from windows to drinkware. In jewelry, glass is used for ornamentation, to make doublets, and to simulate gemstones.