Originally posted by DarkSaint85
I understand what coal and graphite are. And they're two very different things.The only thing they have in common is that they're both black band have carbon in them. But it is impossible to create coal from pure diamond, just by the addition of energy - even disregarding the fancy words toy put in your original post.
You need to add water, add sulphur, add nitrogen etc. They're two completely different materials.
But they are not very different things. As I said, the term coal does not refer to any specific material but to a range of carbon-rich materials at different stages of coalification. It is possible under certain conditions for this process to eventually yield mineral graphite.
Thus, depending on one's definition (there's not a universally agreed-upon one for coal), graphite mineral can indeed be said to be a type of coal. And various amorphous/glassy derivatives of it can be called coal, too. For example, wikipedia lists graphite as a type of coal:
https://en.wikipedia.org/wiki/Coal#Types
Superman is therefore certainly allowed to refer to the polyaromatic carbon material he produced as coal. Although, personally, I would place the term in quotation marks (as I did earlier).