Coal can be obtained through Managing Miscellania by having the player's subjects of Miscellania gather it for them. In order to gain coal, players must store money in the coffers and then set the focus of the subjects on mining. They will mine coal and possibly a few gem stones in the background for the player.
The market price of coal is currently 109 coins. Coal maintained an average stable price of 175 coins prior to June 2009, but gradually rose to over 300 coins in the middle of 2010. After free trade was reinstated on 1 February2011, the price briefly fell to an average 160 coins before it continued to fluctuate near 250 coins until 2013.
A rework of Mining and Smithing was planned for September 2016. However, the rework has since been postponed to 2017 due to player feedback. Coal was planned to only be required for lower tier bars while new secondary ingredients would be required for the new bars. This caused the price of coal to steadily decrease in value, maintaining a 30-day average of approximately 178 coins during September 2016.
Iron ore can be mined at a faster rate which is helpful if players wish to gain some money from mining. It also has a current Grand Exchange price of 378 coins which has a price difference of 269 coins over coal. Because of the increased cost, many players prefer to mine iron instead.
Coal is not an ore. Ore requires extraction to obtain the element while coal is already in its usable form.
In RuneScape, coal rocks have a higher chance of awarding gems than other mined resources. One can observe this in the real world as well. In the real world, coal beds can supply the needed carbon and pressure that gems require to form.
Coal can be obtained through the Mobilising Armies minigame by exploring for treasure using Dwarven squads during a round. Players may also obtain coal as spoils of war.
As a joke around Christmas time, some players give coal to other players. This is a reference to a well known Christmas tradition where coal is given instead of presents to those who have been naughty that year. This was turned on its head during the 2009 Christmas event, where the naughty NPC Tiny Thom was delighted to have been given a lump of coal due to its market value.
Coal rocks in Keldagrim's north-east mine have not been updated like the other coal rocks. They remain completely black when coal can be harvested from them.
It's possible for two players to mine coal from the same rock.
The examine text states, "Hmm a non-renewable energy source!" This is a joke about coal in the real world. Coal cannot be replenished once extracted.