Lambert Cheng "Prima Gold" 24K Gold Panther Overlay Black Onyx Ring

Yellow Gold
By far the most common color of gold used in jewelry, yellow gold is gold in its natural shade. Yellow gold is usually alloyed with copper and silver to increase the strength of the metal. How yellow the metal is depends upon the content of gold. A 14-karat piece of jewelry will have a brighter yellow hue than a 10-karat piece. Likewise, an 18-karat piece of jewelry will have a deeper yellow than 14-karat gold, and so on.

Onyx
Onyx is a variety of chalcedony quartz that features a fine texture with a smooth black color. Some onyx can display white bands or ribbons against black or brown backgrounds. The bands that move through the stone run parallel and onyx is therefore sometimes known as zebra agate. Mined in Brazil, India, California and Uruguay, most onyx today is color-enhanced to increase its depth of color. It ranks a 6.5 on the Mohs Scale and is an ideal stone for carving. In fact, it is a favorite material of lapidary artists.

Onyx was very popular with the ancient Greeks and Romans. The name comes from the Greek word "onux" which means fingernail. Legend says that one day frisky Cupid cut the divine fingernails of Venus with an arrowhead while she was sleeping. He left the clippings scattered on the sand and the fates turned them into stone so that no part of her heavenly body would ever perish. In Greek times, almost all colors of chalcedony were called onyx. Later, the Romans narrowed the term to refer to only the black and dark brown colors, while the reddish brown and white onyx became known as sardonyx. Highly valued in Rome, sardonyx was especially used for seals because it was said to never stick to the wax. Roman General Publius Cornelius Scipio was famous for wearing sardonyx.

Worn during mourning in the Victorian age, onyx is now traditionally given as a 7th wedding anniversary gift. It is thought to increase happiness, self-control, courage, intuition and instincts. The stone is also believed to cool the yearnings of love and decrease sexual desire.

Gold Karat
Gold's softness and malleability make it a wonderful metal to work with when creating virtually any design in jewelry. But this softness can be a drawback as well. To make it stronger and more durable, gold is usually alloyed, or mixed, with other metals such as copper or silver. The higher a metal's percentage of gold content, the softer and more yellow the jewelry piece. The karat weight system used to measure gold in a piece is the same for all hues, including white and yellow gold.

The word “carat” is Arabic, meaning “bean seed.” This is because historically seeds were used to measure weights of gold and precious stones. In the United States, “karat” with a “k” is used to measure gold's purity, while “carat” with a “c” is used in measuring a gemstone's size. The karat mark of gold represents the percentage of pure gold to alloy.