Gold is categorized into different Karats according to the different ratio of gold involvement. Karat or Karatage refers to how much pure gold is included in a piece of gold bar or gold jewelry. The most common terms heard in the market are 24k, 22k and 18k Gold.
The most pure form of gold is called 24K Gold. To explain this easily, you can divide the make-up of gold into 24 units. 24k simply means that 24 out of the 24 units are made of pure gold. In terms of purity, this leads to around 99.0% gold purity, and this type of gold has a bright yellow hue (the color of gold as we know it) distinctive of gold that comes out of the ground. In the market, there are people who would sell 25k, or 26k Gold. Buyers need to be careful of these vendors since they exists no purity higher than 24k. 24K Gold is used in gold bars, gold coins and as parts of some machinery equipment and medical equipment. Jewelers usually don’t use 24k Gold in studded jewelry or other gemstone jewelries.
Along the same concept, 22k Gold refers to a piece of gold that is 22 units of pure gold and 2 units of other types of metal. In this case, the metal alloy mixed in can range from bronze, copper, nickle to palladium. 22k is used widely for studded jewelries as well as in a lot of diamond jewelries.
18K Gold is the most popular choice of gold in jewelries. 18K Gold is comprised 75% of pure gold and 25% of other types of metals, including copper, gold and other alloys. Mixing different ratios of these alloys can create different color effects on the 18k Gold jewelries.For example, Rose Gold and Pink Gold colors can be achieved by mixing in a higher proportion of copper.
Green Gold color can be achieved by mixing in zinc in higher proportions, while White Gold color can be achieved by mixing in palladium and nickel to the alloy mix.The numbers below summarizes the involvement ratio of gold for each gold karatage.
Tips for Gold Buyers
24 karat = 99.5% pure gold and above
22 karat = 91.7 % gold
18 karat = 75.0 % gold
14 karat = 58.3 % gold
12 karat = 50.0 % gold
10 karat = 41.7 % gold