If you're going to fork over a chunk of your yarn money for cashmere, how do you know if it good cashmere? In fact how do you know if it has any cashmere ?
NOTE that a well-made cashmere product should feel soft and this should get better and softer as the piece is worn and washed. If it is too soft in the shop, it will pill and deteriorate rapidly. A good indication is to hold the cashmere piece up at eye level and look along the top surface. There should be a fuzziness above the fabric. If it is around 1mm then it should be fine - anymore and it will pill with minimal use.
So good to know! Life is too short to knit bad yarn.