The bookmark is a ter'angreal recently in the possession of Verin Mathwin.[1]
Appearance[]
The ter'angreal is a thin leather strap with steel weights on the ends, like what is normally used to mark a book, but much longer than usual.
Use[]
Placing the bookmark in a closed book and twisting the loose ends together causes the book to disappear. The ter'angreal works only on books.
Verin suggests that the bookmark was created by someone concerned with concealing their personal journal.