Its a simple emerald mod. It gives emeralds more of a purpose. It is meant to be a simple, but effective mod. It is slightly weaker than iron, but much more durable! The mode includes:
Emerald Sword
Emerald Pickaxe
Emerald Axe
Emerald Shovel
Emerald Hoe
Emerald Helmet
Emerald Chestplate
Emerald Leggings
Emerald Boots
Only for Minecraft 1.12.2