Scientists have discovered a spongy form of calcium carbonate (CaCO3), a material found in limestone, chalk, marble, and the shells of mussels and other shellfish. While most forms of calcium carbonate are hard minerals, this new form is soft and absorbent. The researchers, reporting November 5 in the journal Matter, made the discovery while exploring new uses for leftover mussel shells.
Click here for original story, From hard to soft: Making sponges from mussel shells
Source: Phys.org