In the literature, most of the data available on well-crystallized
and large grain size phyllosilicates refer to their dry
states (see, for example, HELGESONet al., 1978). On the
other hand, most of the data available for poorly crystallized
or small grain size phyllosilicates (i.e., clay minerals) are derived
directly or indirectly from solubility measurements.
These latter data are ofthe fully hydrated states of the minerals
even if HzO is not currently taken into consideration when
equilibrium reactions are written