from lithium fluorhectorite by ion exchange with 1 m solution of magnesium chloride and guanidinium chloride application_number US 25782488 A description it has been discovered that mixtures of two fluorhectorite materials give surprising and unexpected properties in fluorhectorite papers fig1 provides a graphic representation of the synergism where the strength of the mixture 10 90 to 90 10 increases relative to either component alone as shown the tensile strength with pure magnesium fluorhectorite is slightly higher than with pure guanidinium fluorhectorite from fig1 the peak in strength occurs with a ratio of about 60 magnesium fluorhectorite to 40 guanidinium fluorhectorite while not known with certainty it is believed that the very fine particle size of the guanidinium fluorhectorite floc serves to fill in voids between the larger magnesium fluorhectorite floc in the paper thus acting as a binder a starting material for preparing either magnesium fluorhectorite or guanidinium fluorhectorite is lithium fluorhectorite as prepared according to u s pat no 4 239 519 examples 1 and 2 of u s pat no 4 707 298 describe the preparation of guandinium fluorhectorite magnesium fluorhectorite is similarly prepared using mg solutions reinforcing materials useful for preparing articles according to the invention are inorganic fibers.