I am running a campaign where my characters need to destroy a roughly cylindrical stone, about a foot in diameter and a couple feet tall, with a hardness of 7 and 28HP (14 before it is broken). Hardness seems to act like resistance in general, but I would have thought that stone would have even greater resistance to slashing or piercing damage, than to bludgeoning damage. Is there any support for this in the rules, or has anyone just done it anyway?
Relevant rules:
Rules-as-written, I don’t know of anything about hardness applying differently or selectively - where different types of attacks treat hardness differently in pathfinder 2e. It would make sense, though, that a sledgehammer and a dagger would affect a brick differently.
I believe that things were simplified for 2e. Hardness does works kind-of like damage resistance, as you mentioned.
A house rule that particular damage either bypasses hardness, or there is extra hardness for certain damage types sounds reasonable. Especially if that knowledge is available with a Knowledge check.