when camping these to flag my alt wiz, I noticed some things. I did not stay to test my theory further because I disliked the camp, But I thought someone might find this information helpful or useful.
4 pieces of the talisman,
4 diaku classes- each drops different section (I didn't record which diaku dropped which piece, sorry)
they come as warrior(wears chain), rog(wears chain), shaman(only one to cast), or SK(only one to wear plate)
what I noticed killing the rocks PHers was that It seemed the different classes would Pop different diakus.
The rock classes were
Rock Storm(Wizard)- seemed to pop the Shaman/SK
A violent sandstorm(rogue)- Probably pops rog/warr, I killed more of the whirling which worked for me
A whirling sandstorm(warrior)- popped the rog/warr diaku for me
So just remember which diaku classes you looted for your first 2 or 3 sections from and try to kill the right Rocks to get the Leftover diakus you need to pop.

Brick of Ethereal Energy
Ethereal Parchment
Hydrolyzed Ether
Quarter of a Diaku Emblem
Strand of Ether
Uncut Jacinth