Bonus: +6% Damage with Faeblades.
1 - Lorestone
The first stone can be found just right of the dungeon exit.
2 - Lorestone
In order to obtain the second stone, turn right behind the first intersection and head to the end of the tunnel.
3 - Lorestone
The third stone can be found north of the first Thresh.
4 - Lorestone
In order to obtain this stone, you need to have at least 5 points in "Detect Hidden". That way you will see a secret passage on the left side of the corridor (just before the Thresh room). Go through it, head forward and then turn right. The path will lead you to the destination.
5 - Lorestone
The fifth stone is hidden at the very end of the underground. You will see it after defeating two Threshes.