Well, we already know emeralds need a use... How about to craft a new forge block? This interactive block allows you to color your tools and armor, no matter what material the tools and armor are made out of. All you do is dye them depending on the part of the tool or armor, possibly with patterns as well. However, this block can be damaged. It will break after 32 uses. We could also use an enchantment altar, and the enchantment depends on how many emeralds are used. I will add a key for the amount of emeralds per enchantment and the enchantments themselves later.