Qiviut must be mentioned as were on wool. Its Musk Ox down spun into wool.
Highly prized by the inuit, its supposedly much warmer than every other wool. Academic for me though-the price of the stuff is immense.
More info; http://www.qiviut.com/about_fiber_yarn.cfm
Never heard of this before, thanks for the link. Prices are stratospheric!