When gold comes out of the ground it is considered nearly pure and referred to as 24kt pure gold. Gold is mixed with alloys to add durability and strength. How much alloy is mixed in determines the purity. 18K gold has 18K of gold and 6k of alloys to make up the 24k. 14K has 14K of gold and 10K of alloy, 12k has equal parts of gold and alloy, and 10 is predominantly alloy with 10K of gold and 14k of alloy.
Interestingly, what type of alloy is used will determine how the gold expresses itself in color. If a an equal blend of and is used the gold remains yellow in color. If a predominance of copper is used as the alloy, the gold is pink or rose. If a predominance of nickel is used, the gold looks white. If a predominance of sterling silver is used the gold looks green. Iron in the alloy mixture is producing blue gold and an undisclosed alloy is creating purple gold by a company named Azial.
You can see a wide assortment of gold at Davidson & Co. Jewels.
As described above, gold expresses itself as white in color from a predominance of nickel alloy. But if it is 14K gold, the metal mixture is still predominantly gold which is naturally yellow; therefore even white gold has a slightly golden coloration. For this reason, many companies will plate a white gold ring with rhodium, which is a white metal and a member of the platinum family. When this plating wears off, the white gold underneath is revealed. In comparison to the rhodium plating, white gold looks yellow. The plating can be reapplied by us at Davidson & Co. Jewels.