Multiple Item Auras?

[pathfinder_raw]

If a specific magic item, take for example Hellscourge, has a listed aura, I assume that is the only aura detectable. Is this correct? For example, Hellscourge's listed aura is Necromancy. It is, however, an unholy item which has an aura of Evocation.

If correct, then what about a crafted item with two special abilities from different schools?

[pathfinder_raw]

If know one knows directly, does anyone have any suggestions on other resources possibly?

(another thing that came up today in regards to original post ... Hellscourge becomes a Flaming weapon when hamatula hide is worn. So would it take on an additional aura applicable to Flaming?)