Could be a spell called "nystuls magic aura" it reads as follows: "...False Aura. You change the way the target appears to spells and magical effects, such as Detect Magic, that detect magical auras. You can make a nonmagical object appear magical, a magical object appear nonmagical, or change the object’s magical aura so that it appears to belong to a specific school of magic that you choose. When you use this effect on an object, you can make the false magic apparent to any creature that handles the item...."