Very hard to see due to pitch black color and ignites violently at 650 celsius or with fire, burning very fast, can also stick to surfaces, be moved by gel, and expands when heated like BOYL (however the effect is a lot weaker). It should have a very low diffusion rate, and a very low weight, and also absorbs part of the photons, and is harmful to STKM, STK2 and FIGHs. It's tmp value is the yield of the combustion, and when combined with gunpowder or liquid rubidium it will absorb them and it's tmp will increase. It also explodes when SPRK or orange BRAY touches it, and if the former happens, the coal will have a tmp2 of 1, and it will create slightly more heat, as well as more pressure, and will create less smoke. If combined with NITR it will create THRM (which is kinda hard to create in TPT). Nearby oxygen particles will also set it's tmp2 to 1. If "absorbed" by gel the gel itself will become slightly flammable (but not explosive), and burning gel will create a lot of smoke. Flammable GEL should have a tmp2 of 1. And GEL with a tmp above 80 should not be flammable unless exposed to very high heat (>1500 celsius). Well this makes sense I think. And finally coal dust cannot burn or explode while submerged in water or heavy liquids like deuterium oxide or mercury. (coal dust absorbing gunpowder kinda doesn't make sense but idk)