Though all three are made of calcium carbonate crystals, the hard materials include clumps of soft biological matter that make them much stronger. (pnnl.gov)
The presence of that protein makes calcium carbonate crystals form in a nanostructured pattern, rather than smooth and even crystal, study coauthor Marc McKee, a biomineralization researcher at McGill University in Montreal, and colleagues found. (sciencenews.org)
Proteins trapped in calcium carbonate crystals create a compressive force — or strain — within the crystal structure. (pnnl.gov)