The shells, called tests, are made mainly of calcium carbonate, which the animals derive from carbon atoms in the air and water. (discovermagazine.com)
The wonder material graphene, a single layer of carbon atoms with extraordinary properties, has been proposed as one solution. (sciencedaily.com)
The diamond - like structural unit consists of six - sided rings of carbon atoms bonded together in chains surrounded by a halo of hydrogen atoms. (sciencedaily.com)