Normal Aura

By means of this spell, the magical aura of an item can be concealed. The item can weigh up to one-half pound per level of the caster; more massive items are unaffected. Intelligent items, or those with alignments, cannot be masked. To detect magic and similar spells and abilities, the item will appear to be non-magical, with no saving throw. However, if the item is actually held by the detecting creature, then a successful saving throw vs. spell allows the item's true aura to be perceived. Further, an illusionist using detect magic or detect illusion while holding the item receives a saving throw bonus of +1 (which the specialty wizard bonus increases to +2).

The normal aura spell does not block true seeing, nor does it conceal a magical aura from a spellcaster four or more levels higher than the one casting the spell. It will negate Nystul's magic aura (and vice versa) if cast for this purpose.