The Highfire Crown was a major elven artifact of great power. Since the crown was made of the sentient selu'kiira of thirteen high mages, it was a source of near-limitless arcane knowledge. The crown would effectively make its wearer a Grand Mage with access to thirteen supplemental high mages, allowing the wielder to cast nearly any high magic ritual alone.
The selu'kiira belonged to the thirteen Selu'taar that gave their lives to erect the mythal of the Elven Court in 714 DR and bound their sentience to the gems. The crown had no recorded sightings since that day, having vanished in the light of the dawn the next morning.