Yak wool

Soft and fine like cashmere
The fine undercoat of these robust, long-horned pack animals is not yet widely known in the world of hand knitting. It is quite rare, as most yak farmers prefer to use and rent out their animals as pack animals (for example, on Himalayan expeditions) rather than combing them or collecting the wool from fences and bushes. To keep the yarn affordable, it is often blended with other fine fibers, such as silk.