This work introduces a novel facile method to produce shear-stiff, mica-like nanoplatelets by efficient exfoliation. The essence of this procedure is the nonreversible alteration of the interlamellar reactivity of a synthetic fluorohectorite by simple cation exchange. The possibility of switching from highly hydrated to collapsed interlayers permits a highly efficient exfoliation in the swollen state while providing shear-stiffness in the collapsed state. This method restricts cation exchange in the mica-like nanoplatelets to the outer surfaces, which represents a significant advantage for use in nanocomposites as compared to conventional organoclays which contain up to 40%/wt of organocations. It is expected that this new type of rigid, shear-stiff, clay-based nanoplatelets will be superior for reinforcement when used in composite materials like polymer layered silicate nanocomposites or artificial nacre.