3rd Gen Trouble getting to the Magma base in Emerald

[triassicranger]

I'm currently playing Emerald and I've gone to that mountain where you're supposed to access Team Magma's Base, I've walked all around it, I've been carrying the Magma Emblem, but I don't seem to be able to get to Team Magma's Base. Am I doing something wrong?

 

[Ivysaur]

You have to "talk" to a big rock you'll see where a Team Magma member was standing before, after you beat them in the top of the mountain (Mt. Chimney).
Then a door will open, and you'll enter the hideout.

Here is said rock:

Spoiler:

 

[kamehameha300]

just talk to a big on the lower part of mt chimney

 

[Shiny]

You'll need to be facing the rock directly & press 'A', in order to start the event