Rocks are no longer possible to place and so do not count as a building material.
There are 12 different rocks found around Navezgane. They can be picked up by placing the crosshairs over the rock and pushing the E key. Rocks collected in this manner will be added to your backpack as Small Stones and not the actual rock type that was picked up. Using a Pickaxe on rocks will cause them to break, allowing you to pick them up as the correct type. However, except for Rock01 also known as large stone and Rock05, they have no use other than for decoration.
Stone[ | ]
Rock01 and Rock05 differ from all the other rocks as they can be crafted into Stone and placing either one into the centre of the crafting grid will work.