Ground mud runes

Ground mud runes are a quest item used during the Eyes of Glouphrie quest by using a pestle and mortar on a Mud rune, awarding the player with 1 Herblore experience. Adding them to a bucket of sap turns it into magic glue which can be used as a glue to repair a broken machine in Brimstail's cave near the Gnome Stronghold.

Ground mud runes are also used to make Extreme magic potions, by using ground mud runes on a 3-dose Super Magic potion at level 91 Herblore, granting 250 Herblore experience.

Trivia

 * Mud runes are one of the only two runes that can be ground with pestle and mortar, the other are Astral runes.
 * Ground mud runes weighed more than normal mud runes, which like all stackable items weigh nothing. After 10 March 2014 they are now stackable themselves.