Hidden Effect
+10% to Earth Element Magic Spells
-10% to Lightning Element Magic Spells
-2 Avatar Perpetuation Cost for Titan and Earth Spirit
+2 Avatar Perpetuation Cost for Ramuh and Thunder Spirit
guess ppl cant read, if your under attack and reniewing stoneskin it never hurts to put it in a idle set, if you have stoneskin on and are being attacked with normal gear your stoneskin doesnt last as long, if your wearing -Physical damage taken gear while stoneskin is on your stoneskin takes less damage thus lasting longer.. simples
Please dont use this for casting SS, it really doesnt increase it and every time you do it a kitten is drowned. It is only handy to increase your chances of it being cast and not interrupted. Only job that should be doing this is RDM due to their enhancing skill making it far easier to hit the SS cap on a MND build.
The reason why some mages cast Stoneskin with an Earth/Terra Staff is because of the 20% damage reduction. It makes it so you take less damage so it is easier to finish casting SS while you are under attack.