Graphite appears naturally in three forms: amorphous, which is the last stage of the coalification process; crystalline flake, which is used in brake linings and pencils; and lump, used mostly in batteries

Graphite appears naturally in three forms: amorphous, which is the last stage of the coalification process; crystalline flake, which is used in brake linings and pencils; and lump, used mostly in batteries

oalification converts wood into lignite, a process in which internal wood structures can be preserved. Petrification also preserves the original wood structures. Petrification is traditionally known to occur through two preservation processes.

Coal is generally considered a sedimentary rock as it is made up of deposited material (in this case organic matter, mostly from plants) and is eventually covered up by overburden. I'm not going to go into the details of the physical change but the reason black coal might be considered metamorphic is that it has been subjected to more pressure over time which furthers the coalification process.

The order of coalification coal:

peat -> lignite (brown coal) ->sub bituminous -> bituminous ->anthracite (very rare)

everything after lignite is black in colour.

If you need this for a report I'd probably look it up though, its been a while since I've studied coal in depth.

Coal is formed over millions of years through a process called coalification, which involves the decomposition and transformation of plant matter under high pressure and heat. Since this process takes a long time, it is not possible for humans to create coal in a short period of time when we run out. Additionally, coal reserves are finite, so eventually, it will no longer be available as a resource.