Karats are the number of equal parts (out of 24 total) of pure gold. The remaining parts are called “alloy,” mainly consisting of copper, silver, and zinc. Pure gold has a vibrant yellow color, but it is too soft to be used in Western-style jewelry. Alloying makes gold harder and changes its color. It also makes gold cheaper since less gold is used. 18K gold is 75% pure gold. It is used in fine jewelry. 14K alloy contains only 58.5% pure gold, and it is used in commercial mass-production. Very cheap jewelry is made using 12K, 10K, and even 8K gold.