Spidery Sundial

Spidery Sundial is a common archaeology artifact that requires 45 Nerubian Archaeology Fragments to complete. Up to two keystones may be used to complete this artifact.

Description
While the artifact is clearly of nerubian make, it is curious what the cavern-dwelling spiderlords would have needed with a sundial. Could it be somehow attuned not to the actual sun but some light-producing, subterranean mineral? Or perhaps it suggests the divergence of the nerubians and qiraji following the destruction of Azj'Aqir.