But the settings say that its the races that remember the above ground that call it the azure sun. Everyone else calls it the crystal so it seems fair enough that they would come up with diffenrent terms for its phases.
To get things straight, I was referring to the section that Eagel quoted: "Named the Azure Sun by those races that still remember the surface, it emits a radiation that (...)". To me this sounds more like "these people gave it that name", not like "only those who know the old stories call it that". Especially not if taking into account that Hydlaa is referred to as "City of the azure sun". Not undisputable, but seems most likely to me.
It is possible that the different races have different expressions for it in their native languages (more or less interesting to historians only, though). Lemur and Kran would certainly have needed some name for it. Not sure how scientific that would have been, though. Xacha would be most likely to change the name, but seeing that the other races combined outnumber them, it's not sure their interpretation caught on. All in all, as Nikodemus says, this question would need a definition by the settings team, though it's not of high priority to me, as I am fairly sure I can still use dusk and dawn, etc., as explained.
Edit: @UtM: ah, I misunderstood you, then. Sorry for the confusion!