HELP! Secret Passage - iPhone

I have the amethyst stone and glue left, the glue won't go over the empty spot on the box or anywhere else. Is anyone else having this problem? Also, the stone flashes over the little alcove on the bottom on the right side of the screen. need help!

This forum is kinda stinky. There are three different places where I've found posts on this topic but when I search for it, it only returns one forum.

put the glue exactly over the spot with the missing gem and hold it for a second or two, then put the amethyst on it.

then you get to upgrade and spend a lot more time on the forum figuring out the mini games.