Like the exoskeletons of many life forms on earth, the shells in this ocean are composed mostly of calcium carbonate, or CaCO3. Unlike the exoskeletons of many life forms on earth, these shells are massive. Because of this, seashells have become more than just a collector’s item. The calcium carbonate found in these shells can be used in a couple of ways, including medicine and dietary supplements.
Additionally, this material can be used as a building material. Calcium carbonate and its crystalline forms (calcite and aragonite) are better known as limestone, and pure crystalline calcite can be used to make lenses and screens. While the shells do not grow quite big enough naturally to be used this way, we have discovered that by adding a bit of extra CO2 to the water we can increase the amount of carbon available for the organisms to turn into shells.