This should not, however, be confused with wearability or abrasion resistance. Silk will not stand up to the heavy wear that other fibers will. Silk can take on many different appearances. A raw silk fabric may fool you into thinking that it is a cotton or a synthetic. The more refined the silk and the smaller the yarn, the more it resembles the look and feel that we know as silky.
Silk is a protein fiber like wool .
This gives it many of its characteristics. It is sensitive to a range of chemical situations and cannot withstand prolonged exposure to either high alkalinity or to acid or oily soils. It will become brittle with age and exposure to sunlight. The burn test is the best way to be sure. Burning silk will leave a powdery ash and will extinguish itself when the flame is removed, just like wool.