The double migration technique, which is based on mineral formation in an electrical field, was used to synthesize composites of gelatin with calcium phosphate and carbonate, respectively, in order to generate a degradable bone substitute material. Gelatin is integrated in the mineralization process to increase the minerals solubility, in analogy to the formation of the bone mineral dahllite. The mineral formation is affected with respect to the particle size, shown by transmission electron microscopy. Machined polyacrylic barriers increased gelatin stability and allowed investigation of the influence of gelatin barrier position and ion concentrations within the mineralization solutions on mineral morphology and structure by scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. During degradation of the mineral in simulated body fluid, the possibility of an adjustable calcium ion concentration could be shown, which might be useful to manipulate the osteoblast/osteoclast ratio.