Removing all of the impurities in the 10 karat gold will leave
you with 24 karat gold.
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10 karat is 41.67 % gold 14 karat is 58.33 % gold 18 karat is 75
% gold 24 karat is 100 % gold
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Yes you can make 22 karat gild into 24 karat by melting the 22
karat and then remove the impurity - which would most likely be
copper. This means you would have about 91.6% of 24 karat gold and
8.4% copper from the original weight of 22 karat gold