The formation of talc during the dehydroxylation reaction of serpentine minerals

The occurrence of talc which may form during the dehydroxylation reaction of the serpentine minerals antigorite, lizardite and chrysotile has been studied. Several experiments were carried out both ex situ and in situ in order to better understand the conditions of formation of this phase. Talc is observed as a metastable phase only during the dehydroxylation reaction of antigorite and, to a lesser extent, of lizardite. On the other hand, talc formation was not observed during the dehydroxylation reaction of chrysotile because of its corrugated unstable cylindrical lattice that readily prompts the formation of forsterite.