A fire rune obtained in the Runespan is created by siphoning fire esslings, fireballs (both with 14 Runecrafting) and fire storms (with 27 Runecrafting), requiring one rune essence and giving 17.5, 34.8 and 42 experience respectively.
Fire runes are worth 0.25 Runespan points. They can also be used to chip chaos esshounds. They will disappear and be converted into points if you leave the Runespan.
Players that try to bank any runes or essence from Runespan receive the message "A magical force prevents you from banking this item."