Chronos Crystals

Aren liked keeping notes, but hated actually writing everything down. Eventually she figured, what better way to record her thoughts than to literally record her thoughts.
Chronos Crystals are powerful, heavily enchanted and enhanced Arcane Crystals that are capable of containing an individuals thoughts and memories. Much like peering into a window of the past, someone interfacing with a Chronos Crystal is able to view the recorded memory through the eyes of the individual who was recorded. While some powerful mages have been known to use these devices to help memorize complex spells and rituals, others use these expensive tools to perserve cherished memories, such as those of loved ones.
While Chronos crystals are a remarkable feat of arcane engineering, they are incredibly difficult and costly to construct, particularly if one wishes to perserve a large number of memories. There is also a risk of brain damage if an individual does not properly interface with the chronos crystal, and damaging a crystal can render the memories stored within heavily fragmented and incomplete.