What is the physical differences between charcoal and limestone?

well, first off, charcoal is made up of carbon atoms while limestone is made of CaCO3 molecules, in the form usu of the mineral calcite. charcoal is soft, quite brittle and black and porous. it is usually formed by pyrolysis of mat'ls like wood. limestone is a sedimentary rock, much harder than charcoal, and formed by thousands of years of sedimentation. there are many limestone formations around the world.