Karat Gold

Buyer's Guide » Stones & Metals

Gold has been used in jewelry and decoration throughout human history. Prized for its rich yellow color, corrosion resistance, malleability, and rarity, gold has always been treasured.

Gold used in jewelry is almost always alloyed with other metals. These alloys make gold stronger, harder, easier to melt, easier to fashion into jewelry, and can alter its color as well. This alloyed gold is commonly referred to as karat gold. The amount of gold in an alloy is described in karats which divides the metal into 24 parts. Pure gold is 24 of 24 parts gold and is therefore 24 karat gold.

Most gold jewelry sold in the United States and Europe is either 14K (14/24 or 58.3% gold) or 18K (18/24 or 75% gold). 14K gold is more popular in the U.S., while 18K is the norm in Europe. In the Middle East and Asia, 22K gold and higher is popular.

Gold jewelry will almost always have a stamp somewhere on it that indicates the karat or fineness of the gold. In the U.S. the stamp will be a number followed by a K (i.e. 14K or 18K). In Europe a number indicating fineness is used (i.e. 750 for 75% pure or 18K gold). Some jewelry made for export will have both stamps.

The advantages of lower karat gold (14K and lower) are its lower price and greater hardness and durability. The drawback of lower karat gold is its tendency to tarnish, and a higher propensity for allergic reaction (Gold itself in non-allergenic, but the alloying metals, especially nickel, can cause a reaction). Higher karat gold (over 14K) is more expensive and less likely to produce an allergic reaction, but is softer and less durable.

Pure gold is, of course, a striking yellow color. The different colors of gold are produced by the various metals used to alloy it. In the United States we most often see yellow and white gold, but other colors are available and sought after.

Yellow gold is produced by using a combination of alloy metals (zinc, nickel, copper, silver, etc) so as not to overcome or alter the natural yellow color of pure gold.

White gold is produced by using a white metal, usually nickel or palladium, in the alloy. White gold is usually slightly harder than equivalent karat yellow gold, but also more brittle. White gold, especially higher karat white gold, is usually off white to slightly yellow. In order to get the bright white, lustrous color, it is plated in rhodium. Rhodium is a hard, durable, and expensive member of the platinum group metals, and lends itself well to plating.

Rose or pink gold is produced by adding copper, and green gold is made by adding silver to the alloy. Rose gold was very popular in Victorian period jewelry, as well as, in Retro period pieces. In old jewelry, we often see beautiful combinations of different colored gold.

return to buyer's guide