I noticed when I use the console to turn an element to coal, it spontaniously combusts. It doesn't burn, but turns into fire, as if I typed "!set type ____ fire", but I really typed "!set type ____ coal". I'm hoping this will be fixed in a future update, as it limits what can be done.
Coal is a very "odd" element in turns of properties... as ^^^ said, it's mainly about the life property, coal burns for a set amount of time, before "disapearing" into fire. The life of coal when spawned is 110, so you will have to go "!set type all coal" and then "!set life coal 110"