| The organic carbon content of coal increases gradually with increasing coalification degree. |
| During coalification, peat undergoes several changes as a result of bacterial decay, compaction, heat and time. |
| The effect of increasing pressure due to depth of burial is not considered to cause coalification. |
| The most widely accepted explanation is that coalification takes place in response to increasing temperature. |
| Ibarra JV, Munoz E, Moliner R FTIR study of the evolution of coal structure during coalification process. |
| Coal rank indicates the progressive alteration, or coalification, from lignite to anthracite. |
