Clear Rock
Clear Rock is a command that players can give their citizens to remove rocks from the map and collect stone. This is the fastest way of obtaining stone, and will most likely be necessary to use when needing it while a player's settlement has just been created.
Once the Clear Rock command is chosen, the player can click and drag a selection box around any rock embedded in the ground. In the selection box, any non-rock tiles will appear as red, and valid rock tiles will appear as blue. Once a selection has been made, any free citizens not performing a job will immediately arrive to the selected area and collect the stone from the grounded rocks.
If the player has chosen a settlement location where wood is very scarce, this command may not be of much use.
Difference in natural rocks
There are two types of rocks that can be collect in the game, though each one requires a different method to do so. The two types of rocks can be seen in this image:
The green arrows point to stone that can only be obtained via stone mines, while the red arrows point to rocks that can only be collected through the Clear Rock command.
In-game description
"Removes rocks on the map. Yields the resource stone."