Hydrothermal treatment of mixtures of Fe(II) sulfide gels with Mg/Al hydroxide gels at 200°C, under reducing conditions, results in the formation of a molecular composite material with a composition range around 2Fe1-xS · 1.7[(Mg0.7Al0.3(OH)2]. The material comprises positively charged layers of Fe1-xS alternating with incommensurable, negatively charged hydrotalcite layers. Four distinct structural modifications were identified by TEM and electron diffraction, all with approximately the same composition: (i) A plate-like, (pseudo)hexagonal phase, the hydroxide layers of which have aH ≈ 3.0 Å and the sulfide layers aS ≈ 3.7 Å, indistinguishable from synthetic valleriite. (ii) A second plate-like phase comprising (pseudo) hexagonal hydroxide layers with aH ≈ 3.1 Å and (pseudo-)tetragonal sulfide layers with aS ≈ 5.3 Å, corresponding to the reported plate-like form of natural tochilinite. (iii) A uniquely disordered, nanotubular crystalline phase, probably derived from the (ii) form, and corresponding to the reported tubular form of natural tochilinite. (iv) a modification of the plate-like form (ii) in which the two layers are rotationally “disordered” or multiply twinned.