In Australia, the three major fibres used in carpets are Nylon, Wool and polypropylene (polyolefin). Some are made of blends e.g. 80% / 20%.
Despite the competing claims of fibre suppliers, no one fibre necessarily makes a better carpet. Good carpets are made from good raw materials and components, coupled with the skills of the manufacturer to produce a properly constructed carpet using these components.
For this reason, there is no simple answer to the ‘which fibre is best’ question and it is unwise for consumers to base a buying decision on fibre alone. let your personal preferences rule your decision on fibre, colour, texture, feel and style.