I'm reading a book Agent Viola gave me. See?

Essence Crystals and Where to Find Them

It's very interesting. You can enhance your Essence on your own, or you can use an Essence Crystal. When a person who has found enlightenment dies, their remaining Essence sometimes manifests as a crystal. But the crystals are very delicate, so there are only few who can utilize them.

Player, if you find an Essence Crystal, please let me inspect it. It would help greatly with my research.

Player: Accept

Do you have an Essence Crystal?

I'd love to inspect one.

Player: "As a matter of fact, I do."

Oh! So this is what an Essence Crystal looks like!

It stopped shining as soon as I touched it....

Maybe you have some kind of special power, Player.

Player: "Who knows?"

Oh! Oh wow! It vanished!

Do you feel any stronger now, Player? Did you see the light when it vanished? I think you absorbed it, Player!

That was fascinating! I'll have to write this down.