How do you pass the part to make the gem?
'Pry open the door with someone inside', 'Pry further and watch the lion' and then wait. I mean that last one literally, it isn't an option to click. There should be a message that says "It should be some time before he does something interesting". I'm not sure how long you have to wait, after you've done it once as long as you keep to that save file you will automatically skip the wait.
That should get you on track as long as you have already read the journal entries and spell book.
I will add, just walk away from your computer/phone while waiting. The game will progress without you and there's no negative effect to waiting for what feels like forever (It's just so painful to physically wait that long... I'm a speed reader, I don't have time to sit still!). When the scene has finished playing out, it'll leave the option to "return to the hallway" or "approach the lion".
If you wait longer, nothing bad happens, so go make a sandwich or something and just read the text when it's done.