Gemstone Key D

 is an Item in Outward.

Description
"Part of a set of 4. Activates the Main Console in the Forgotten Research Laboratory."

Acquired From
To reach this key, you will need to defeat the Giant Horror to reduce the level of corruption in the area. Head back through the door and take the first right, then leave this small room and head directly south until you come to an opening on your left (east). This is the exit to Antique Plateau, take the exit and you will find the key ahead.