Dwarvish Translation Guide

Teaches you dwarvish.
Overview
The Dwarvish Translation Guide is a special item unlocked after donating all four Dwarf Scrolls to the Museum. Once obtained, it lets the player understand the dwarves’ language, opening up direct communication with the 
After it is acquired, the guide appears in the player’s menu on the Special Items & Powers tab. It is a progression item rather than a crafting recipe, despite its item type being labeled as crafting on the rewards screen shown after turning in the final scroll.
Because the guide is tied to collecting all four scrolls, the Dwarf Scrolls themselves are the gating requirement. A useful way to finish the set is to revisit Mines floors 15, 55, and 95, which have tillable soil near the floor entrance; the elevator makes it easy to repeatedly return to these floors and farm for 

Official description
Teaches you dwarvish.