Charge Earth Orb is a skilling spell which requires level 60 Magic and the standard spellbook to cast. It requires 30 earth runes, 3 cosmic runes and 1 unpowered orb, and grants 70 experience per cast. It transforms an unpowered orb into an earth orb, which can then be added to a battlestaff in order to create an earth battlestaff. It can only be cast at the Obelisk of Earth, located in the Wilderness portion of Edgeville Dungeon. It can only be reached by traversing Taverley Dungeon. Due to the high earth rune cost, it is recommended to use a staff of earth or equivalent when casting this spell.
As the Obelisk of Earth is located in the Wilderness, care should be taken while using it. It can be quickly reached by using the Dungeoneering cape to teleport to the Edgeville Dungeon chaos druids dungeon then heading north-west then heading south upon reaching the black demons. This requires level 99 Dungeoneering. Alternately, players who have completed the hard Wilderness achievements can use the shortcut to reach the Obelisk of Air by heading north of Edgeville, climbing down the ladder, then heading south. Otherwise players must traverse the entire dungeon.
The obelisk is surrounded by poison spiders, so anti-poison protection is recommended. Additionally, players will be attacked by black demons, thugs, chaos druids, deadly red spiders and skeletons depending on the route taken.
Assuming all materials are bought on the Grand Exchange and a staff of earth is used, casting Charge Earth Orb currently yields a profit of 2,893 coins, or 41 coins per Magic experience gained.