Nickel deposits are generally found in two forms: sulphide or laterite. About 60% of the world's known nickel resources are laterites. The remaining 40% are sulphide deposits.
There are two main types of nickel sulphide deposits. In the first, Ni-Cu sulphide deposits, nickel (Ni) and copper (Cu) are the main economic commodities - copper may be either a co-product or by-product, and cobalt (Co), Platinum Group Elements (PGE) and gold (Au) are the usual by-products.
The second type of deposit is mined exclusively for PGE’s with the other associated metals being by-products.
Nickel sulphide deposits can occur as individual sulphide bodies but groups of deposits may occur in areas or belts ten’s, even hundreds of kilometers long. Such groups of deposits are known as districts. Two giant Ni-Cu districts stand out above all the rest in the world: Sudbury Ontario, and Noril’sk-Talnakh, Russia.