Charged Crystal

If you're confused like I was, all 6 Arcane Energy Samples and the Uncharged Crystal can be found within the Archival Assault Delve.

The Arcane Energy Samples aren't interactable or lootable items. Once Myi Koo gets near one of the spheres, you'll see him shoot a little arcane beam towards the sphere, giving you credit. The Arcane Energy Samples can be found all over the place and look like blue /purple spheres that are slightly larger than the smaller ones that are scattered around the delve.

The Uncharged Crystal was found in a boat, on an upper level in the delve and was an interactable object.

Hope this helps!

for me, the uncharged crystal was in a boat on the level above the bottom level.

You first have to speak with [npc=237996] and they're next to the Serrated Peaks phase conduit at /way 51.22, 48.59, not in the Delve or near the Delve entrance.