A block that you can find in Minecraft is called Tuff. It’s a light grey block that you can find in your world, so long as you’re digging under Y=16. The only way you can mine this block and receive it is to use a pickax. If you use anything else, the block drops nothing and is instead deleted. What can you do with Tuff in Minecraft, and what is it used for?
Beyond using Tuff for decoration and adding it to your many piles of blocks inside your base, there’s not much else you can use for it. If you want to add it to a wall and use it for any particular decoration project, that’s the best way to handle it. It doesn’t feature in any crafting projects following Minecraft update 1.17 in the first part of Caves and Cliffs.
What Tuff does work as in your Minecraft is operate as a way for deepslate to appear. When a Tuff block occupies a space, there’s a chance for diamond, gold, iron, lapis lazuli, or redstone ore to also be there, and when it does, Tuff becomes a deepslate block instead. Tuff needs to have that ore value to hit it, and if it does, the deepslate block spawns into your world.
Although when you mine the Tuff block from a space, it doesn’t do anything, the real heart of the matter is that it does create deepslate ore. You just can’t interact with it to change anything at all. It’s mostly the world generating that deepslate. If you’re near Tuff, chances are there could be a few blocks of deepslate nearby.