[aruanan]

There’s no question that coal is the result of compressed plant material. I was active in the Illinois Basin and the evidence of leaves was obvious.

I didn't say there were no fossils, just that there are too few and the isotope ratios are wrong.

[Eric in the Ozarks]

The stuff is something like 260 million years old so we'll have to await a higher authority to say for sure.
We operated a hydrocyclone wash plant to lower the sulfur and ash in the raw coal. The "coarse reject" material was very neat stuff, full of pyrites, partings and something we referred to as 'cannel coal,' which was dull colored and brittle. It was heavier than the regular coal, which made it sink in the cyclone bath. At one of our pits where the coal was about 90 feet deep, there was a rider seam, high in the hill, well above the shale, laying in the clay layer. Part of this had burned at some point, probably ignited at its crop edge by a prairie fire.