Calcium salt composite/calcite or spar is one of traditionally used therapeutic material for hard tissue repair and regeneration due to its abundant calcium content. There are several types of calcite (fluorspar or calcite fluoride, cobaltoan calcite, etc) exist in the nature and their therapeutic effects are different depending on their basic properties. For instance, calcium carbonate based calcite used to treat damaged hard tissue in the traditional medicine. Here, we would like to investigate characterizations of three different types of calcites gathered from the nature. For this purpose, collected calcium salt composites ( calcite, fluorspar, feldspar ) were examined their surface properties, morphology and size by the scanning electron microscopy. Energy-dispersive X-ray spectroscopy was used to determine their elemental analysis and X-ray diffraction was carried out to characterize their crystallinity structure. Based on the calcium contents, calcium carbonate-based calcite was selected to form nano-sized calcite and study their toxicity by using mesenchymal stem cell. Throughout this study, we identified properties of three different calcites and successfully reduced size in nanoscale which helps to use in the future treatment of osteoporosis or to stimulate osteogenesis.