Biomimetic mineralization can lead to advanced crystalline hybrids under ambient conditions. To date, the synthesis of the prismatic layer with stiffness and wear resistance nonetheless remains an elusive goal. By taking advantage of seeded mineralization, we developed an effective synthetic approach to different types of prismatic-type CaCO3 thin films. The synthetic procedure contains a three-step pathway: coating a polymer substrate, deposition of a granular transition layer, and mineralization of a prismatic overlayer. The synthetic prismatic overlayers can exhibit structural similarity and comparable hardness and Young's modulus to their biogenic counterparts found in mollusk shells or turtle eggshells. Furthermore, overgrowth in the presence of soluble polymeric additives leads to the prismatic thin films with micro-/nano-textures and emerging under-water superoleophobicity. Hence, seeded mineralization can afford the mineralized layers with multiple structural functions. Moreover, this approach could proceed on fibrous substrates to obtain crack-free thin coatings, so that a modified nylon mesh could be employed for oil-water separation driven by gravity. This study highlights the crucial role of the granular seed layer in promoting overgrowth of the prismatic layer. This biomimetic approach based on seeded mineralization opens door for deposition of hierarchical mineralized thin coatings on planar and fibrous substrates. Moreover, it could be readily extendable for the synthesis of advanced thin coatings with a broad spectrum of engineering and functional constituents.