This gem contains a mote of elemental energy. When you use an action to break the gem, a water elemental is summoned as if you had cast the conjure elemental spell, and the gem's magic is lost.
This gem contains a mote of elemental energy. When you use an action to break the gem, a water elemental is summoned as if you had cast the conjure elemental spell, and the gem's magic is lost.
Dungeon Master's Guide (2014), p. 167