With the Emerald Tools mod, emeralds in Minecraft will become not only a local currency, but also a valuable resource for crafting. From them it will be possible to create the same tools as from other materials using similar recipes.
Emerald Tools Mod for Minecraft 1.15/1.14.4
Moreover, in some respects they will surpass even diamond objects. For earlier versions of Minecraft, there is this mod under Forge.
1.15 – Emerald-Tools-1.8.1
1.14.4 – Emerald-Tools-1.4.4