When most people think of gold, the image that comes to mind is of a metal with a soft, yellow glow. Indeed, the incomparable golden hue of this precious metal has been part of its appeal for centuries. But for the gold jewelry connoisseur, there are more shades of gold available than just yellow - and in a spectrum of different hues. The tint the gold takes on depends on the metals it is mixed, or alloyed with. Here are the main shades of gold:
• Yellow gold - This is gold in its natural shade. It is by far the most common type of gold used in jewelry. Yellow gold used for jewelry is usually alloyed with copper and silver to strengthen it. The warm glow of yellow gold works with virtually any outfit, any skin or body type and any gemstone. How yellow a piece is will depend on its gold content. Generally, 14 karat gold has a brighter yellow than 10 karat gold; 18 karat gold has a deeper yellow than 14 karat gold, and so on.
• White gold - White gold has become very fashionable in recent years as many consumers have opted for the cool, contemporary white look over the classic yellow look. White gold has the same properties as yellow gold, but is mixed with different alloys to give it its white color. Generally, white gold is created by using a nickel or palladium alloy, zinc and copper. Sometimes, white gold is plated with an even whiter metal, such as rhodium (a rare member of the platinum family) to enhance its appearance. A white gold setting can enhance the look of white diamonds and put a modern twist on a traditional standard.
• Rose gold - By alloying just copper with yellow gold, metalsmiths can create gold with a pink, blush-like tint, which experts say lends a soft, flattering effect to the skin.
• Green gold - This alloy is created by mixing silver, copper and zinc to yellow gold.
The other types of gold jewelry include gold-filled, gold-plated and vermeil. Gold-filled refers to a layer of gold mechanically bonded to a base (non-precious) metal; the gold content must be at least 1/20th of the total weight of the piece. Gold-plated merchandise has a coating of 10 karat gold or higher applied to a base metal by electrolysis. Vermeil is jewelry that is made by applying a layer of karat gold to a sterling silver base.
To keep the classic appeal of yellow gold but update it with a more modern look, many women are opting for two-tone styles that combine white and yellow gold within the same piece. These types of pieces are considered very fashionable and have become particularly popular in bridal jewelry in recent year.
For an even more original look, some women are choosing jewelry which combines three colors of gold (most often yellow, rose and green) within the same piece.
Gold is so soft and malleable that it can be melted and shaped to create virtually any design. But this softness also makes pure gold less than desirable for jewelry usage - which is why it is usually alloyed with other metals such as copper or silver to make it stronger and more durable.
The gold content in a particular alloy is expressed in karats (abbreviated as K or KT). Each karat is equal to roughly 4.17% of the total alloy. Generally, the higher the percentage of gold content, the softer (and yellower) the piece. The karat weight system used for white gold is the same as that used for yellow gold (white gold is mixed with different alloys to give it a white color).
Here are some common gold karatages (karat weights) and the corresponding percentages of actual gold:
• 24K represents pure gold (100%) and is rarely used in jewelry.
• 21K is 21/24ths gold content, or 87.5% gold. Jewelry of this karatage or higher is rare in the United States, although it is far more common in parts of Europe, the Middle East and Southeast Asia.
• 18K is 18/24ths gold content, or 75% gold. This is a popular karatage for higher end jewelry in the United States, Europe and other regions, and its usage is expanding in North America.
• 14K is 14/24ths gold content, or roughly 58.5% gold. This is by far the most commonly used karatage in the United States (and perhaps the world) and provides a nice balance between gold content, hardness/durability and affordability.
• 10K is 10/24ths gold content, or 41.7% gold. This is an increasingly popular karatage sold by many U.S. mall jewelry chains, department stores, discount stores and other mass market venues because it offers budget-conscious consumers precious metal jewelry at more affordable prices than the standard 14K. It is also the lowest gold content that can be legally marked or sold as gold jewelry in the United States. Often used in rings because they tend to be worn every day and experience many knocks and thus require an exceptionally strong alloy.
• 9K is 9/24ths gold content, or 37.5% gold. This is a popular karatage sold by mass marketers in England and other regions, although it cannot be marked or sold as gold jewelry in the United States.
Sometimes, gold of a lower karat weight is plated in higher-karat gold to enhance its color. This is perfectly acceptable as long as the jeweler discloses this fact and you pay a fair price. Keep in mind that gold plating will wear off over time and your jewelry may need to be re-plated.
To determine the karat weight of a particular piece of jewelry, look for the quality mark. Generally, pieces will either bear the stamp of their karatage based on the U.S. or European system. The U.S. system uses karat designations (24K, 18K, 14K, 10K, etc.) Europe uses number designations which correspond to the percentage of gold content. For instance, 10K is marked "417" for 41.7% gold; 14K is marked "585" for 58.5% gold; 18K is marked "750" for 75% gold, etc.

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