Build "natural" rocks mod?

[abborre]

So we can plant trees, we can sculpt the terrain, so how about being able to place large stone formations, from boulders, to large bodies of rock, to mountaintops?

 

I think something like this would be very useful if you for example wanna build some kind of tunnel underground, or make your structures blend into the environment more. So let's get discussion going about it.

 

Exactly how would this work? Clearly, "building" a enormous slab of rock can't cost the same amount of stone as you'd get from quarrying a normal rock of equivalent size, because there's no way you could fit that much stone in your inventory without being overencumbered. So the player-made rock formations would have to be a lot "cheaper". So if they can be broken through with a pickaxe, they should obviously yield little to no stone, to keep it consistent.

 

Another question could be what kinds of requirements for this sort of thing, should it require some special tool with it's own build menu, or should it require some unusual resource to help separate it from normal stonecutting?

 

Also, would it be overpowered? Like, if I made 4 different Plains-type megalith pillars and just build a giant castle on top of them, would that be unfairly useful? Maybe kinda, but that would require a lot of resources and effort, and there are other ways to make very secure bases, so it doesn't seem like a huge problem.