I found a pattern that calls for Shokay Shambala [100 % pure yak down; 164 yd per 100g hank]. Not only is this yarn hard to find it is a fortune! Needing 14 hanks at $32.00 a hank would make a VERY expensive shawl!! So, I was looking for a substitute yarn and would love to see if anyone here would have one to recommend. The shawl gauge is 16sts/24 rows=4" square.
What weight is it? You should just try to find some yarn of the same weight. If if has any special characteristics, you should look for those to (i.e, eyelash, mohair, slub, shiny surfaces, etc.) Remember to do a gauge swatch to determine your gauge with the new yarn.