Oligomeric Pro-Hyp-Gly- (POG-) peptides, wherein the collagenous triple helix is supported by C-terminal capping, exhibit silica precipitation properties (O, Hyp = (2S,4R)hydroxyproline). As quantified by a molybdate assay, the length of the covalently tethered triple helix (number, of POG units) determines the amount of amorphous silica obtained from silicic acid solution. Although lacking charged side chains, the synthetic collagens precipitate large quantities of silicic acid resulting in micrometer, sized spheres of varying surface morphologies as analyzed by scanning electron microscopy. Similar precipitation efficiencies on a fast time scale of less than 10 min were previously described only for biogenic diatom protein's and sponge collagen, respectively, which have a considerably higher structural complexity and limited accessibility. The rninicollagens described he provide an unexpected alternative to the widely used precipitation conditions, which generally depend on (poly-)amines in phosphate buffer. Collagen can form intimate connections with inorganic matter. Hence, silica-enclosed collagens have promising perspectives as composite materials.