Brinepickle's Delightful Duplicator

Target: a non-magical object no heavier than 1lb.

To cast this spell you must first create a rough copy of the object you intend to duplicate. The copy does not need to be precise, but it must be composed of the same materials and have a value at least equal to the original. For example, if you intend to copy a book, a stack of papers sandwiched between cardboard and leather will be sufficient. 

You set the original object on one side of the mirror, and the replica on the other so that it sits about where the reflection appears to be in the mirror. By channeling magical power, you then slowly transform the rough facsimile into a copy of the original. All text, illustrations, engraving and decoration are clearly and legibly duplicated, and the copy functions identically to the original in every way.

The copy is not entirely perfect, and any creature familiar with the original item who succeeds in an Intelligence (Investigation) test against your spell save DC will spot the imperfections and know it is not the original.