The structural formula of talc from the Trimouns deposit, Pyrenees, France

A sample of talc (T111) from the Trimouns deposit, in the Pyrenees, France, was studied by various spectroscopic methods (FTIR, NMR, EPR and Mossbauer ), as well as HRTEM and X-ray diffraction, in order to investigate the exte nt of minor substitutions in the tetrahedral and octahedral sites. Substitu tions cause a deficiency in tetrahedral charge, compensated by an excess in octahedral charge, ensuring an electroneutrality of the structure. The cha rge deficiency on the layer of tetrahedra explains the active interaction b etween talc (used as filler) and polymer.