Whilst the carpet construction is attributed to "Berbers", a nomadic tribe idigenous to north Africa, this is not strictly true! Berber carpets as made by "Berbers" were more like multi-coloured axminsters.
Berbers by Victoria, Penthouse and Gaskells (Apokria 6 ply)
Man made berbersBerbers are made from man made fibres as well as wool. Polypropylene is the main textile because it simulates woolen colours much more accurately than nylon (more popular Stateside).
This brings the price of berbers right down. Polypropylene berbers look and feel somewhat contrived and "caustic" unless they have some wool mixed in with them (at least 20%). Polypropylene berbers are more suitable for letting properties and offices where feel is less important than practicality.