What is alloying of gold? Why is it done? What is meant by 24 carat gold?

Explanation

Pure gold is seldom used for making ornaments, as it is a soft metal with a high melting point. Thus, it is alloyed with other metals such as copper, silver, brass, cadmium, etc. This makes the gold workable at lower temperature. Furthermore, it increases the hardness and hence, the ornaments formed from alloyed gold, do not get deformed easily.
However, alloying the gold reduces the purity of gold. Thus, in order to know the purity of gold in the article of alloyed sample, it is expressed in carat/karat. Where, 1 carat/karat = 4.1666 g per 100 g of alloy.
For example, 22 carat/karat ornament of alloyed gold contains `4.1666 xx 22 = 91.666` percent of pure gold. The same way, 24 carat/karat gold contains `4.1666 xx 24 = 99.998` or 100 per cent of gold.