Bone tissue engineering is an interdisciplinary field where biomimetic scaffolds are used for bone regeneration. Biomimetic scaffolds chemically, structurally and mechanically imitate natural bone tissue. Scaffolds must be biocompatible and bioactive with suitable resorption properties. Biomimetic scaffolds represent an alternative solution for conventional methods that are used in the treatment of bone injuries and diseases. Silicon naturally exists in the human body and promotes proliferation and the differetiation of osteoblasts, thus it promotes regeneration of natural bone tissue. In this research, samples of calcium carbonate are synthesised with a different amount of silicon dopant which will be used as a precursor of hydroxyapatite, a mineral phase of natural bone tissue. All as-prepared samples are heat-treated at 600 °C. Samples are characterized before and after heat treatment with X-ray diffraction analysis (XRD) and infrared spectroscopy with Fourier transformations (FTIR). The software DIFFRAC. SUITE TOPAS V.5.0., with the fundamental parameters approach, was employed for Rietveld refinements. As-prepared samples are triphase systems of calcite, aragonite, and vaterite, while after heat treatment system is composed of calcite and calcium silicate.