This branching or bamboo coral has parts composed of both protein (the black parts) and calcium carbonate (calcite - the white parts.) Image courtesy of Exploring Alaska's Seamounts 2002, NOAA/OER.
This branching or bamboo coral has parts composed of both protein (the black parts) and calcium carbonate (calcite - the white parts.) Image courtesy of Exploring Alaska's Seamounts 2002, NOAA/OER.