I completed all the tests in Shar's temple. I collected everything I needed to collect. To activate the elevator i put two gems into the thingy, just to see, that I need 3 of them to open the big and final door. What did I miss. Where did I go wrong. If I seriously wasted 1 gem on the first thing at the elevator, why does the game allow me to do that?? Can someone PLEASE help me, because I am so tired and can't seem to find any help.

Thanks in advance. <3