A blacksmith can break this open for you. These geodes contain a wide variety of Minerals. It's one of the helmets commonly worn by dwarves. The thick metal plating protects them from falling debris ...

Geodes can be obtained by breaking rocks in the Mines from levels 1-39 especially. They're also dropped by Duggies. You can find them in Fishing Treasure Chests, or receive them as gifts from the ...