Gold Karat Information

Since ancient times, the purity of gold has been defined by the term karat, which is 1/24 part of pure gold by weight. Pure gold is equivalent to 24K. Gold purity may also be described by its fineness, which is the amount of pure gold in parts per 1000. For example, a gold ring containing 583 fine gold has 583 parts (58.3%) gold and 417 parts (41.7%) of other base metals. Federal Trade Commission rules require that all jewelry items sold in the United States as gold shall be described by "a correct designation of the karat fineness of the alloy."

Karat Gold Parts Gold % Gold
9kt 9 in 24 37.5%
10kt 10 in 24 41.67%
12kt 12 in 24 50%
14kt 14 in 24 58.33%
18kt 18 in 24 75%
22kt 22 in 24 91.67%
24kt 24 in 24 99.99%

Weighing Precious Metals

The weight of a piece of jewelry is a factor that helps to determine its value. It is important because it is an indication of the purity in an item of jewelry. While Grams (g) and pennyweights (dwt) are the units of weight most commonly used in weighing precious metals, We Buy Gold uses the pennyweight standard (dwt). Precious metals are almost always weighted in the troy system of weights, where one pound troy equals twelve troy ounces and twenty pennyweights equals one troy ounce.

The Avoirdupois weight system, where one pound equals 16 ounces, is used in the United States for most everything except precious metals. The following table summarizes useful weight conversions.

Weight grams (g) pennyweight (dwt) troy ounce (oz t) ounce avoirdupois (oz av)
1 gram (g) 1 0.643 0.032 0.035
1 pennyweight (dwt) 1.555 1 0.05 0.055
1 troy ounce (oz t) 31.103 20 1 1.097
1 ounce avoirdupois (oz av) 28.3495 18.229 0.911 1