What does Karat gold mean, as in 10k, 14k, 18k, etc?
Pure gold is defined as 24k, and can be formed into pure gold jewelry items, as if frequently done in the Far East. However, pure gold is generally considered to be too soft for many jewelry applications, so other Alloy metals are added for strength. The amount of Alloy added to a given amount of pure gold determines the purity–and value–of the resulting metal. The higher the gold content, the more valuable the metal. All gold alloys, primarily used in jewelry construction, are expressed in fractional parts of 24k. For instance, 10k gold is 10/24 pure, or 10 parts of pure gold + 14 parts of alloy. Since 10 divided by 24 is .4167 or 41.67% pure gold is in all 10k gold items. Similarly, 14k is 14/24 pure or 14 parts pure gold + 10 parts alloy and results in 14k being 53.88% pure gold, while 18k gold is 75% pure gold. Pure gold is a highly inert metal, and has almost no tendencies towards oxidation or tarnishing. Gold alloys below 50% pure, such as 10k gold, can show some oxidation–tar
