For the people, depending of the region they usually use different gold quality, like example in Latin America the 18k gold is more common but in north America the 14k gold is the king for that reason we want to go deep into the purity of gold.
we have different types of Karats, 24k, 18k… what is that? the reason for this is an equivalency, the karats of the gold are different for the gemstones (ct) in this post we only explain for Gold (Kt), example: 1 karat represents 1/24 part of the total alloy. that’s why we call pure gold 24k because the equivalent is 24/24 parts of gold.
18k Gold = 18/24 parts of gold or 3/4, that represents 75% pure Gold in that alloy.
14k Gold = 14/24 parts of gold or 7/12, that represents 58.4% pure gold in that alloy.
10k Gold = 10/24 parts of gold or 5/12, that represents 41.7% pure gold in that alloy.
but sometimes we heard the people talking about the numbers like 750 fineness Gold? what is that? that number represents the law, Millesimal fineness that means parts per thousand in the alloy.
999.999999 The purest gold ever produced, 24k Gold
916 This represents 916 thousandths of gold per 1000 of alloy, common in gold coins like American gold Eagle 22k Gold
750 This represents 750 thousandths of gold per 1000 of alloy, or 18k Gold.
583.3 This represents 583 thousandths of gold per 1000 of alloy, or 14k Gold.
417 This represents 417 thousandths of gold per 1000 of alloy, or 10k Gold.