Players can also find uncut gems while mining, which can increase profit. A charged amulet of glory can help members find even more gems, but it is not required. A gem is obtained at around 1/282 chance when mining a rock (without an amulet of glory).
Although coal only takes 30 seconds to respawn after being mined, and the world switching tactic could still be used, the last option would be Wilderness Coal Mine only if the Mining Guild is overcrowded and/or Barbarian Village Mine is deemed insufficient. The Wilderness Coal Mine has 34 coal rocks, but it is in level 9 Wilderness, just north-west of Edgeville, and is bombarded with aggressiveskeletons (regardless of Combat level) and the always-looming threat of a player killer. Since it is in the Wilderness, players should not take anything they are not prepared to lose. It's also suggested for players to have a decent Defence and Hitpoints level and mine with caution. Furthermore, players should bring a few pieces of food and a Melee weapon in which the weapon is optional, but it could still help. Also, members could wear the Serpentine helm, which could help ward off threats. After a full inventory, banking can be done by either running south-east into Edgeville or using an Amulet of glory to teleport there depending on membership status, but it's strongly advised to only use this mine as a last resort as well as any other risky and dangerous locations.
All in all, players can get 200-500 pieces of coal every hour predicated on levels and efficiency. Thus, the hourly profit margin ranges from 35,400 to 88,500.
Due to constantly changing prices on the Grand Exchange, some information in this article may or may not be current. It is strongly recommended to check the live prices on the Grand Exchange before making large investments in any method. All prices on this page are cached, meaning it is possible that they appear out of date. To force a new cache of this page, click this link. If a money making method is out of date, you can edit it or leave a message on the talk page.