Opal Stud Earrings in 18kt Gold Over Sterling

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."

POST/CLUTCH: An earring with a post insert and a slide-on clutch backing to hold it in place.

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.

CABOCHON: A style of cutting gemstones to achieve a smooth, domed surface with an absence of facets.