Clue geodes are rocks that can be found while training Mining (excluding the Motherlode Mine). Searching them will give players a clue scroll of the same difficulty as the geode given. Like clue scrolls, players can only have one of each type of clue geode in their possession.
If a player does already have other tiers of clue scroll in their possession, it does not increase the chance of getting the tier of clue scroll which they don't have yet. 
If a player possesses a clue scroll of the same difficulty as the clue geode, they will be unable to search the geode until the clue scroll is no longer in their possession. There are four types of clue geodes: