The Magus will be busy studying those stone tokens you gathered, but I know he'll eventually want examples of their counterpart: bracers of binding. These are set around the wrists of actual elementals, and bind them into the mage's service.
Hunt elementals in the ruins of Dalaran and gather their Bracers of Earth Binding, and the Magus will be pleased.
You found them. I trust the elementals from which you removed these bracers were amenable?
Hm...death has not only stopped my heart, but robbed me of my comedic timing, it seems.
Well thank you, <name>. You serve the Magus, and hence the Dark Lady, well.