The Minium Stone is the sole tool added by Equivalent Exchange 3. The Minium Stone converts some blocks in the world to other blocks, and can be crafted with certain resources to convert them into other resources. While converting blocks in the world does not use up the Minium Stone's durability, using it in crafting does.
The Minium Stone also contains a portable crafting grid that can be accessed by pressing C with the Minium Stone selected in the hotbar.
With the Minium Stone selected in the hotbar, certain blocks can be right-clicked to convert them into blocks considered "equivalent" in value. The target block can be changed by pressing G, though hovering over a non-equivalent block will reset the target block. The chart below details which blocks are considered equivalent:
|Block 1||Block 2||Block 3||Block 4|
The following recipes detail what the Minium Stone can be used for in crafting (all recipes are shapeless):
Block of Gold
Block of Diamond
Note that, while Not Enough Items lists far more recipes for the Minium Stone, most don't actually work when crafted. This page has only the recipes that do work.