One of the more recent additions to Minecraft is the addition of smooth stone. As the name implies, this is a stone block with a smoother look to it than regular stone. If you want whatever you are building to have a different look compared to the many mines, this is what you have to do.
First, you will need to collect a bunch of cobblestones, a furnace, and any fuel for that furnace. Cobblestone can be obtained by mining stone blocks with any pickaxe. A furnace is made by collecting eight blocks of cobblestone and crafting a furnace at a crafting table. On PC, put cobblestone on every block except the center block to craft the furnace.
When the furnace is crafted and placed, you can put your remaining cobblestone in the top slot of the furnace. The max it can hold at a time is 64.
Now you need fuel to smelt it. You have quite a few options to fuel your furnace. Any wood item can be used as fuel on its own, or wooden blocks can be made into charcoal that burns more efficiently. Coal can be found at any level underground and occasionally can be seen from the surface. Blaze rods and lava buckets can also be used as fuel in a furnace. Lava buckets will smelt 100 blocks at a time.
Now that you have your fuel source, you can place it in the bottom slot of the furnace. If both slots are filled and compatible to be smelted, it will automatically start smelting. The arrow in the middle will supply until the first block is done, and then it will begin on the next one. With cobblestone in your ingredient slot, you will begin receiving regular stone.
Now that you have your regular stone, either wait for your furnace to finish smelting or make an additional furnace. Make sure you have your fuel in the bottom slot and put the regular stone in the top slot. Now the stone will be changed into smoothing the stone, and you have a different block to build with.