Like Sailor Moon and Tuxedo Mask, every Planetary Senshi and Moon Senshi in the Solar System has their own crystal, or suishou, that is powerful above and beyond an ordinary Sailor Crystal. Each crystal has three properties which make it uniquely powerful:

Healing

Each crystal has the ability to heal. As well as patching up wounds, they can grant immortality and resurrect the dead--assuming the victim's body has not been destroyed.

Abstract Idea

Every crystal represents an idea, something which can't be measured. It could be knowledge or love or purity; the crystal can grant a human the qualities that crystal embodies. Of course, used improperly, the one endowed with those qualities can become inbalanced by them...

Element

Crystals also represent an element, a physical force which can be used as a force of attack against an opponent. Fire, Entropy, Plants--as long as it is something which has a physical presence, it could be a crystal's element.

Each crystal is enormously powerful; in a pinch, a senshi could effect an entire planet with their crystal, though doing so would drain their energy immensely--and, of course, they must be on good terms with the rest of the three powers for their crystal to work at all...