@Enkidoh (don't feel like quoting. I'm using a bluetooth keyboard on a tablet and the touch screen stops responding soooo)
In the quest In the Eye of the Beholder, the reason Krile gives as the Crystal Eye being more pure (which is the wording Matoya used not Krile), is due to the fact that it was made with more of Hydaelyn's power than any of the Crystals of Light in this current age. Whenever Hydaelyn would give an Echo user a Crystal of Light she was giving off a "sliver of her power" SIC. (In English)
The reason I'm guessing that ours isn't as powerful now is because each time she slices away at her power she becomes weaker. Even now it's been since we got all of our Crystals back In heavensward that we've heard from her DIrectly and Indirectly through the Word of Mother when we sent Minfillia to the First to stop the flood or when she merges with... but i don't know if that can be counted.
I know I didn't add the figure at the end the last story update, while we all can pretty much guess that it was Venat/Hydaelyn that showed up to us as we were walking away and told us it was all up to us... It hasn't truly been made official and well I don't like making it an absolute until it is said it was her.