Shell Piece

A chip of calcium carbonate from a living organism’s shell. Grown by reacting calcium with carbon dioxide on a matrix of bio-vinyl. The shell was weakened by acid before it finally splintered. This could be a sign of recent climate volatility and acidifying oceans. Before Earth’s Holocene Collapse and the resulting Expansion, shell-forming organisms helped capture dissolved carbon dioxide from the ocean and return it to the planet’s crust, to one day be released again by volcanoes. Modern exoconchology has identified shell-forming organisms on most Earthlike worlds. True thalassic water worlds, with their kilometers-deep oceans and dense layers of pressure ice blocking access to the rock below, do not supply enough calcium for traditional shellforming to evolve.