Diorite is used to make polished diorite and for decoration as well.
To make Diorite you will need to get Nether Quartz and Cobblestones and then have to use Crafting Table. Please follow the following steps to make Diorite.
In order to make Diorite, the basic item you need to find and get is nether quartz. Go into the nether to get at least two nether quartz using pickaxe.
After that the next required item that you will need to get is cobblestone. You have to get at least two Cobble stones. Use your iron pickaxe to get these stones.
Now you need to use the crafting table to craft a diorite block. Go towards the crafting table and open up 3*3 crafting grid. Add two cobblestones and two diorites on the grid in the same way as shown in the image below. You will get two diorite blocks in the right-side box of the crafting table. Add these diorite blocks in your “ready to use” stock.