Hirsch Natur's "trekkies" were designed to be the ideal hiking socks.  

Materials: 85% organic wool*,15% organic cotton*

Made in Germany. 

*please note that these socks have several small, elastic threads woven into the very top section to hold them up around the ankle.  The manufacturer includes these elastic threads because without them, socks made from only natural fibers will not stay up around the ankle.  The elastic threads have minimal, if any, contact with the skin.  The fabric itself is made from 85% organic wool,15% organic cottonl (no synthetic materials)*

Sizing: