The grinder item can be used as a tool for faster mining.
To use your grinder, select the grinder item in your inventory. Notice that a number appears in the hotbar, specifying the durability of the grinder. A regular grinder (G) has a durability of 2000, while a SUPER GRINDER (G) has a durability of 20000. Durability decreases by the number of mined blocks whenever more than one block is mined at the same time. The durability is a property of the player rather than a property of the grinder. This means that placing the grinder down and picking up a different one will maintain the same durability.
Currently, two block types can be mined with a grinder: stone and wood. When stone is mined with a grinder, surrounding stone in a small area is mined as well. When wood is mined with a grinder, a sequence of additional wood blocks is broken, following the pattern of tree generation. Surrounding leaves and vines are mined as well, still following the tree generation pattern. A simple animation plays when wood is mined with a grinder.
The grinder does not currently do anything special in block form.