This fingering weight yarn from Isager is made with 63% Alpaca, 26% Silk and 11% Yak.  Each 25g ball is approximately 164 yards.

From Isager "ISAGER SOFT FINE has a core of silk on which a strand of alpaca and yak is added as a loopy boucle, which is then brushed to make a fluffy yarn. " And " ISAGER SOFT FINE contains wool from yaks and the depth of the colors derives from the dark color of the yak wool." And "Its softness compares with Silk Mohair, kniting with this yarn, however, is a completly different experience, especially when knitting with one strand only."  

The yarns with brown labels are undyed/natural colors.  The yarns with black labels are dyed.  

Photos from Isager.