High-Purity Calcium Carbonate in Freshwater Clam Shell

Science  03 Jun 1966:
Vol. 152, Issue 3727, pp. 1368-1370
DOI: 10.1126/science.152.3727.1368


The calcium carbonate in freshwater clam shells is simlilar in purity to that designated reagent grade. A simple reprecipitation of the shell extract results in a product having less Sr and Mg than reagent grade CaCO3. Clams are harvested commercially, and discarded shells are a high-quality raw material for the production of CaCO3.