NOVELTY - Preparation of highly pure calcium carbonate comprises using shell bowls found in waters around Island; adhering a material to the cleaned shell from the sea bottom at the outer protein matrix of the shells; mixing the shells with ammonium chloride; selectively and completely separating the calcium carbonate from the dissolved solution and quantitatively filtering and drying the calcium carbonate in water.    USE - The obtained calcium carbonate is useful in the synthesis of European pharmacopoeia calcium salts, which are useful in human and veterinary medicines and in cosmetics (claimed). The calcium salts are also useful in food and feed industries.    ADVANTAGE - The calcium carbonate obtained is highly pure. In this method, all the impurities are effectively and carefully dissolved, filtered, quantitatively precipitated and removed environmentally. In the conventional methods, the acids used for the dissolution of calcium raw material are not environmental friendly and the neutralized undesirable byproducts are left behind; and the methods are more complicated and more expensive. The large quantities (annual) of the shells that results from the fish factories amounts to 20000 ton, which were wasted earlier and by this process these residual substances are used as regenerating raw material in the preparation of the calcium carbonate. In this method, small quantities of reagents are used and the method recycles the raw material. The method does not form any residual content (waste). The method completely avoids the emission of the carbon dioxide and the energy consumption is less than the conventional procedures (all claimed.)    DETAILED DESCRIPTION - Preparation of highly pure calcium carbonate (which fulfills the substance criteria of European pharmacopoeia monograph) comprises using raw material, preferably shell bowls (ocean clam shell), which is found in waters around Island; cleaning the empty shells, after obtaining the shell's meat; adhering a material from the sea bottom at the outer protein matrix of the shells, where the material is heavy metal oxide, which is to be removed; mixing the shells with ammonium chloride and heating oxides to soluble metal chlorides and removing from the shell surface by washing with water or alcohol; dissolving the calcium carbonate of the conches in special method for further removal of the existing organic substrate and impurities at the shell surface and effectively filtering the obtained impurities; selectively and completely separating the calcium carbonate from the solution; quantitatively filtering and drying the calcium carbonate in water and the used insoluble alcohol; purifying the remaining substances in the solution (where the consumption of water and chemicals are avoided by this procedure and the aggressive chemicals are not used) and regenerating shell raw material, which is used consistently for the preparation process and quantitative synthesis of European pharmacopoeia calcium carbonate; where the calcium carbonate of ocean clam shell is extremely pure and fulfilled its origin form of the criteria of European pharmacopoeia; where in this method, all the impurities are effectively and carefully dissolved, filtered, quantitatively precipitated and removed environmentally; and the method can also use other sources of calcium carbonate, which exist in large number. Subsequently, the European pharmacopoeia calcium carbonate is used for the whole pallet of the organic and inorganic calcium salts under maintaining the purity criteria as raw material based on European pharmacopoeia calcium compounds; where in the previously used procedures: the acids used for the dissolution of calcium raw material are not environmental friendly and the neutralized undesirable byproducts are left behind; or a complex, expensive and residual substance is associated with the use of less pure raw material.