The 1834 Tiara of Pope Gregory XVI was a papal tiara given to Pope Gregory XVI.
The tiara was unique due to the nature of its decoration, which involved three crowns containing outstanding large trefoils shaped from gold and inlaid with heavy jewels.
The new style of design was copied in the later Palatine Tiara given to Gregory's successor, Pope Pius IX, by the Vatican's Palatine Guard in 1877.
Gregory's tiara was one of the most worn in the papal collection. Pius IX, Pius X and Pius XII all wore the tiara. It is unknown if Pope John XXIII ever wore it.
Popes ceased to wear papal tiaras in 1963, although their usage has not been formally abolished. Future popes could decide to wear papal tiaras, including the Tiara of Pope Gregory XVI.