the magnetic properties of silicates and phosphates are compiled in subvolume 27i. while subvolumes 27i1, 27i2, 27i3 and 27i4 (already published) deal with orthosilicates, sorosilicates, cyclosilicates, and inosilicates, respectively, the present subvolume 27i5 deals with phyllosilicates. subvolume 27i5 has been spilt in two parts a and ß; part 27i5a discusses gillespites, apophyllites, natrolites, micas, smectites and related silicates. further subvolumes are dedicated to other types of silicates (tectosilicates) and to phosphates. - silicates are very complex systems, covering large classes of minerals as well as synthetic samples. their crystal structure is discussed and atomic positions are given. in addition to magnetic properties, results of neutron diffraction studies, nuclear gamma resonance, nuclear magnetic resonance, x-ray absorption spectroscopy, transport properties, dielectric and optical data are reviewed.