Yak and Cashmere has about the same micron count , and it has a similar overall texture. It lacks the elasticity of wool, but it has loft and incredible warmth for its weight. Cashmere is precious and arduous to produce; It is the lightest natural wool. Like no other natural fiber, cashmere wool creates a unique feeling of naturalness and well-being on the skin. The only source of true pashmina is the Changthangi goat, a special breed of cashmere goat native to the high valleys of the western Himalayas. From its soft, gentle warmth to its hefty price tag, it has been a staple fashion must-have for those with deep pockets during many centuries and continues to top wish-lists today.

The U.S. Wool Products Labeling Act of 1939, as amended, (U.S.C. 15 Section 68b(a)(6)) CCMI defines cashmere as:
(A) the fine (dehaired) undercoat fibers produced by a cashmere goat (capra hircus laniger);
(B) the average diameter of the fiber not exceeding 19 microns (a measure of fiber diameter and, conceptually, softness)
(C) containing not more than 3 percent (by weight) of cashmere fibers with average diameters that exceed 30 microns.
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