Is it possible for a diamond to revert back into a block of charcoal?

if the formation of a diamond is a physical change then is it possible to change it back?|||no, but with sufficient heat a diamond will turn into carbon dioxide, leaving no ash behind. And in the absence of oxygen, a diamond will sublime, or evaporate.|||Yes it is. Actually diamonds degrade and go back to their charcoal state Over time, however, the process is extremely slow and thus, we can't really observe it.|||No, because the structure of the Carbon changes irreversibly (within an observable period, that is) with pressure.|||no it takes millions of years to make a diamond. it doesn't just go back.