#"Calcium carbide"# is the calcium salt of acetylene, #HC-=CH#, i.e. #Ca^(2+)""^(-)C-=C^-#. It is produced from lime and coke at high temperatures. This is purely inorganic carbon, but organic chemistry features both Grignard and lithium reagents (and other metallated species), polar organometallic species, with some ionic character.