A quartet of crystals infused with pure elemental energy. Each is formed with equal parts Negative Energy and two adjacent physical elements – as follows:
| Elements | Name |
|---|---|
| Air + Fire | Heat |
| Fire + Earth | Magma |
| Earth + Water | Silt (or “Mud”) |
| Water + Air | Frost |
The four crystals were gathered by the Voyager crew and used to release the imprisoned Fire Elemental Lord.