Item from Harry Potter by J.K. Rowling
A beautiful silver tiara inscribed with 'Wit beyond measure is man's greatest treasure' — Rowena Ravenclaw's lost diadem, turned into a Horcrux by Voldemort and hidden in the Room of Requirement.
Ravenclaw's diadem was lost for centuries after being stolen by Rowena's daughter Helena and hidden in a hollow tree in an Albanian forest. Tom Riddle, ever the charmer, extracted its location from Helena's ghost — the Grey Lady, Ravenclaw's house ghost — by feigning sympathy for her story. He traveled to Albania, found the diadem, murdered an Albanian peasant, made the diadem a Horcrux, and returned it to Hogwarts by hiding it in the Room of Requirement during a job interview with Dumbledore (which he didn't get). It sat in the Room of Hidden Things for decades, invisible among centuries of accumulated junk, until Harry found it during the Battle of Hogwarts. It was destroyed by Fiendfyre — cursed fire that Crabbe cast in the Room of Requirement and couldn't control, killing himself in the inferno. The diadem cracked and the Horcrux was destroyed, though not by any plan.
An elegant silver tiara — delicate metalwork set with a large sapphire at the center. The inscription 'Wit beyond measure is man's greatest treasure' runs along the band in fine script. Said to enhance the wisdom of whoever wears it. Tarnished and dull after centuries hidden among junk in the Room of Requirement, it looked like just another piece of forgotten treasure in the mountain of discarded objects.
Also known as: Ravenclaw's Diadem, the Diadem, the lost diadem, Rowena Ravenclaw's diadem