We definitely need to think about this. We have to find a logical way of doing something like this in survival mode (i.e. what sort if item one would carry in his inventory in order to place a boulder etc)
For a boulder wouldn´t it be the most "logical" way to have a full stack of rocks in your inventory? Same for the ore-rocks - a full stack of i.e. iron.
Of course its not "logical" to suddenly have a massive chunk of rock in front of you when you were just a few secs before carry a bunch of smaller stones with you. But its as close as you can get (i guess).
You could even consider to use that as advantage for storage of certain rawmaterials. 1 rock = 64 stones // 64 stones = 1 rock - or - 1 tree = 20 wood = 1 wood stack