Now, how pure is this 22k gold? Let’s do a simple mathematical calculation:

24k Gold=100% Pure Gold
Thus,22k gold = = 4.167% Pure Gold
Thus ,22k Gold =(4.167*22)=91.67% Pure Gold

Out of the 100% only 91.67% is pure goldin 22k gold. So, what does the other 8.33% consist of? These consistof metals like Silver,Zinc,Nickel and other alloysjust as we explained earlier,The addition of these metals make the overall mixture a little harder and thus helps in making the jewellery more durable. This 22k gold is still not hard enough though it can be used for plain gold jewellery it is not strong enough to hold diamonds & gemstones in studded jewellery (read why 22k gold is not used in studded jewellery in detail).And thus,generally studded jewellery is manufactured in 18k or lower,like 14k, 10k, 9k, ets. Based on the calculations already explained above,

18k Gold =(4.167*18)=75% Pure gold
14k Gold =(4.167*14)=58.33% Pure gold
10k Gold=(4.167*10)=41.167% Pure gold

Are we making senseyet? We certainly hope we are. Carrying on. There are two things to be understood here-First, the hardness of the metal keeps increasing as the percentage of gold in the metal compositions goes down. Second and one of the other important aspectswhich we haven’t yet discussed , the colour of this metal composition start getting duller . it must also be understoodthat purity can sometimes be mentioned as a combination of3 numerals, For example

24k=99.9% Pure=999
22k=91.6% Pure=916
18k=75% Pure=750
14k=58.3% Pure =585