ABSTRACT
The serpentine-mineral group is constituted by three main minerals: antigorite, lizardite, and chrysotile. They are hydrous magnesium phyllosilicates having the approximate formula Mg3Si2O5(OH)4 (Bailey, 1980). The basic structural unit is an Mg-rich octahedral sheet tightly linked on one side to a single tetrahedral silicate sheet, the so-called T-O layer, whose stacking produces the three-dimensional structure. The crystal morphologies range from planar (lizardite) to alternating waves (antigorite) to cylindrical rolls (chrysotile). For a detailed description of the crystal structure of serpentine minerals, see Guggenheim (see Chapter 1 of this book by Guggenheim).
