**2. Classification of natural fibers**

Natural fibers are the result of geological processes or are produced in the bodies of plants and animals. A general but not exhaustive evaluation of such fibers as potential reinforcing materials in composites is based on their origin:


#### **2.1 Fibers resulted from geological processes**

Asbestos is the only natural fiber produced by geological processes widely used as reinforcement in composite materials. It is a fibrous silicate mineral. There are six types of such fibrous minerals, including amosite, crocidolite, tremolite, chrysotile,
