Mussel Shells Vs. Soft Calcite (IMAGE) Cell Press Caption This photo compares dried and ground mussel shells (left) with the soft calcite material (right). Credit Jennifer Murphy Usage Restrictions Credit required License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.