Each item in Minecraft has a unique ID assigned to it, known as an item ID, this can be used in commands to spawn the item into the game. The item ID for smooth sandstone in Minecraft is shown below:
The Smooth Sandstone item can be spawned in Minecraft with the below command. Cheats must be enabled before this will work.
Below is a table of the tools that can be used to break Smooth Sandstone blocks, and the speed it will take to break at (in seconds). This is calculated with the formula (1.5 * Block Hardness) / Tool Multiplier.