Legendary Gem question

[Ceronys]

If you put your gem in the LFR version of the weapon, when you get the real version or even heroic version of the weapon, can you take the gem out of the LFR version to put in your normal mode/heroic version? Limit on how many times? Would only need a maximum of 2 I guess. Once for when you get normal mode and once for when you get heroic.

[Rivin]

You can't take it out, but you can buy as many gems as you need for 10k each after you get the first.

[Glurak]

mh where can i buy a new one ? wrathion say nothing like this and cant find the option to buy a new gem

[Galbrei]

Wrathion himself sells them, you gotta talk to him tough, say you want to "augument" your stats or something.