EGLANTINE TIARA c1832. The coronation diadem of Queen Caroline of Bavaria. It is a "double decker" diadem constructed from an earlier tiara plus an elgantine rose crowning layer. The height was designed to be on par with Empress Josephine's coronation tiara. (Picture in color + the earlier tiara, worn by Queen Therese, here http://www.royal-magazin.de/german/bayern/eglantine-diadem-tiara.htm
The front portion of the King George IV diamond diadem. It was commissioned by that King of Great Britain to wear as a circlet over his Cap of Maintenance upon his arrival at Westminster Abbey for his Coronation in 1821. It has never been worn by a King of Great Britain since, but has been worn by every Queen of Great Britain since - including Her Majesty Queen Elizabeth II who wears it more than any other single piece in her collection
DIAMOND FOLIATE & FLORAL TIARA, LATE 19TH CENTURY. Designed as a graduated series of swags each surmounted alternatively with floral and foliate motifs. Each floral and foliate motif detachable, accompanied by five brooch fittings. (Sotheby's)
The parure was made by C.M. Weissshaupt in 1840. It uses 26 emeralds King Christian VI gave to Queen Sophie Magdalene in 1723 and 41 emeralds that belonged to Princess Charlotte of Denmark. This tiara is part of the Danish Crown Jewels so it cannot be taken outside of Denmark or be worn by anyone other than the queen.