Silicate and Aluminosilicate Minerals that Form Fibers

SILICATE AND ALUMINOSILICATE MINERALS THAT FORM FIBERS 

The most important of these groups is the serpentine mineral group, because it includes the fibrous mineral species chrysotile, which is the most common fibrous mineral and the one most widely mined, processed, and manufactured as asbestos. 

At least seven of the minerals belonging to the serpentine mineral group, occur in fibrous forms. Table 2.2 lists the varieties, together with the crystal chemical data needed to identify them. 

Chrysotile is commonly fibrous whereas the other common serpentines, lizardite (a polymorph) and antigorite, are usually platy or massive, and rarely occur in fibrous forms. 

The crystal structures of all the minerals in the serpentine group contain the same basic building blocks. The basic unit is composed of a silicate sheet of composition (Si205) , in which three of the O atoms in each tetrahedron are shared with adjacent tetrahedra (Fig. 2.2A), and a nonsilicate sheet of 

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