Done by: Chua Tsao Harn (4) 1A3

 There are many types of gold, but they are mainly classified by their purity.

 They have a distinct difference: purity.  12K gold is made up of 50% gold or interpreted as 12/24.  18K gold is made up of 75% gold or interpreted as 18/24.  The purest gold is 24K gold, which is made up of 99.9% gold.

 Gold can be pure but they are normally not pure when made into jewellery or gold bars as pure gold is too soft to be made into gold bars or jewellery.