Adventuring underground can sometimes lead to dead ends, but they are not truly dead ends if there is a chance that any stones blocking the way can be removed. Normal weapons are useless for this task, but with a rock hammer, the situation changes. A smaller, specialized version of the common hammer, this tool can reduce boulders to small stones in no time, clearing the way. These stones then even can be used as ammunition for slings: namely sling stones.
This makes rock hammers especially useful in dungeons, where caved-in passages can mean either a death sentence at worst, or a long detour at best.
In Savage Empire, the rock hammers found in Eodon (which were literally "rock hammers" -- constructed with stone striking surfaces) could be used to break off small stones from larger boulders—a task necessary to retrieve a blue stone for Topuru, to get him to tell the Avatar where the Urali Tribe was. In addition, the hammer itself could also be used as a serviceable weapon (1-5 damage), better than an obsidian knife (1-4 dmg) but not as efficient as a club (1-7 dmg).