Deepslate

Grimstone is a stone variant that functions similar to cobblestone or blackstone.

Breaking
Grimstone can be obtained only by mining it with a pickaxe. When mined using any other tool it drops nothing.

Natural generation
Grimstone makes up the majority of the solid blocks generated below y = 0 in the Overworld. From y = 0 to y = -7 stone is gradually replaced by grimstone until all of the stone below y = -7 is replaced by grimstone.

Usage
Grimstone can be used as a substitute for cobblestone in the deep, as it can be used to craft stone tools, brewing stands, and furnaces. It can also be used to repair stone tools using an anvil. It can also be used to craft polished grimstone and chiseled grimstone.

Trivia

 * Grimstone is a sedimentary rock.
 * Similar to grass blocks, the orientation of the texture varies depending on the coordinates.