Originally posted to Google+ in June 2016:
Diadem of Clear-Mindedness
A shining band of silver whorls, studded with commonplace jewels. In the center of this band is a single, polished purple stone; gaps along the length of the diadem suggest additional stones were once affixed.
The Diadem of Clear-Mindedness clears away your errant thoughts and steadies the mind — giving you focus for the task at hand. When you Prepare Spells, treat your Level as 1 higher when calculating how many Spells you can prepare.
Rumors suggest the diadem was fractured some time ago and the magic stones that power it were scattered, collected by malicious spellcasters looking to increase their potential. If these rumors are true, it is likely that each stone restored to its setting on the diadem would act as an additional +1 to the wearer’s effective spell-caster level when Preparing.