Hey I've getting the second magma orb by letting a day pass and going back but it never respawns can I get some help?
Usually the problem with obtaining a second such artifact is due to the fact that you either Celica is not sufficiently friendly with Nel, or you do not have enough experience in using artifacts.
In my case, this artifact became available simply on the next game day.
I try to follow the recommendations from the books in Agranor's library so that Celica develops all her skills and attitudes. Then the gameplay occurs easily and without problems.
In this case, try going to the guild, talk to Bert (and with Edgar if available), and also visit the bartender and the fortuneteller.
For Celica will need the help of some characters and their quests must be completed (it is difficult to indicate exactly here, because it is not known which quests you have already completed and what skills you have already mastered).