The Endurium Window is a window you can build (the Endurium kit).
In-game description
An endurium wall with a framed pane.SHOWN IN THE BUILD RING
Building it
It costs 2 
Stone, 1 
Endurium Ingot, 2 Earth 1 Fire spirits. It needs 4 Jewels first. Take it down with DISMANTLE to get its cost back (see Building).
