Gold Karat Information
24 karat = 100% gold
No other metals are mixed with the gold
18 karat = 75.0% gold
Recommended for fine jewelry
14 karat = 58.3% gold
The jewelry standard
12 karat = 50.0% gold
A hard gold for jewelry
10 karat = 41.7% gold
The legal karat limit considered as real gold in the United States
Pure gold is too soft for the stresses of every-day wear, so it is alloyed with a mixture of metals like silver, copper, nickel, and zinc to give it strength and durability. Karatage, noted by a number followed by "k" indicates how much of the metal in a piece of jewelry is gold. Karatage is expressed in 24ths, making 24k gold 100% gold.
Two tone gold is simply white gold and yellow gold, or rose gold that is rapped together in the same jewelry item. This type of arrangement is more complex and usually comes at a slightly higher price.
Yellow gold is measured the same way white gold is measured. So, an 18kt yellow gold ring contains 75% pure gold, just as an 18kt white gold ring contains 75% pure gold. What makes yellow gold different from white gold, or rose gold is the alloy mix. Yellow gold is made by mixing pure gold with alloy metals like copper and zinc. White gold is plated to make it look whiter, yellow gold's color is more dependent on the percentage of gold it contains. 18Kt yellow gold has a higher degree of richer yellow color than 10kt yellow gold.
Gold was also highly prized in prehistoric times and may have been the first metal used by humans. An effort to produce gold from other substances was known as alchemy and was the fore bearer of modern chemistry. Gold has been an important commodity in times of inflation since it cannot be produced like currency, thereby retaining its value.