On Magic Obscura is a book in Divine Divinity.
Location[]
Located in the abandoned house in northern Aleroth, to the west of the graveyard, next to the Magic mirror.
Transcript[]
ON MAGIC OBSCURA
by Mardaneus the Healer.
*Unfortunately most pages of this book have been torn out. Maybe Mardaneus did this by himself in his madness, so the evil forces shouldn't profit from his great knowledge of magic and magical artefacts. Only one section is complete and makes sense to you.*
Magic Mirrors are far more common than any other objects made by magicians. The making of Magic Mirrors was once part of the earliest education for young wizards on their entrance to a magic school or circle.
You can use the Magic Mirrors to duplicate certain magical gems. Unfortunately, the Magic Mirror must be destroyed during this ritual, so you will only get one chance at successfully completing the spell.
So, how do you use a Magic Mirror? It's very simple indeed, my faithful pupil. First you have to find a small natural pool, deep enough to submerge the Magic Mirror completely. On being covered by the water, the Magic Mirror will vanish completely. Do not be alarmed. This is part of the magic.
When the mirror vanishes, simply drop the magic gem you wish to duplicate into the same pool and the magic will do its work instantly. The copy will be perfect in every way. Use your Magic Mirror wisely.
But one word of warning: there are far more false Magic Mirrors in the world than real ones these days.