The purity of gold is defined either in karats or fineness. A karat is 1/24 part of pure gold by weight, so 24-karat gold is pure gold. To find the percentage of gold in an object when the purity is stated in karats, multiply the number of karats by 100 and divide by 24. For example, 12-karat gold is 50 percent pure gold. Alternatively, the fineness is the amount of gold in parts per 1,000, so pure gold has a fineness of 1,000. A gold object containing 800 fine gold, or a fineness of 800, is 80 percent gold.
There is no higher form of gold than 24K and you must be aware of this before you go to a dealer who might tell you that they’re selling you 25K or 26K gold. Since this is the purest form of gold, it is naturally more expensive than 22K or 18K gold. However, this type of gold is lesser in density as compared to gold of a lower karatage which makes it soft and pliable. Hence, it is not suited for regular forms of jewellery. Coins and bars are mostly bought of 24K gold purity. 24K gold is also used in electronics and medical devices such as those used for children suffering from ear infections who are fitted with gold tympanostomy tubes that are known to improve aeration of the middle ear.
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