|Materials||10 limestone bricks, 1 magic stone, 1 Arceuus signet, 5,000 blood runes, 5,000 soul runes|
|Examine text||A limestone altar imbued with the corruption of the dark.|
The Dark altar is built in the Achievement Gallery of a player-owned house as a place where players can switch their spellbook to the Arceuus spellbook. Other players can use the altar, provided they at least have 60% favour with Great Kourend's Arceuus House.
|Item||Exchange price||Total price|
|10 x Limestone brick||2,100||3,323,588|
|1 x Magic stone||986,488|
|1 x Arceuus signet||N/A|
|5,000 x Blood rune||1,440,000|
|5,000 x Soul rune||895,000|
- The book on the altar contains morse code, which can be translated as "darkness corrupts".