Despite the description, crystals can not be used for any kind of healing. I assume that is just a reference to reality (a belief by new age hippie types in healing properties of crystals), since they are not required for the healing aura enchantment (or anything else in-game, besides the Fire Curse enchantment).
I edited my post (while you were replying) to delete the comments about dragon and zeppelin crystals, since you would have specified if that was what you were referring to.
