Cameca's brooch

Cameca's brooch was a piece of jewelry given to the First Doctor by his fiancee, Cameca, as he and his companions prepared to depart 15th century Mexico. (DW: The Aztecs)

The Doctor did not initially seem to want the brooch, but impulsively took it at the last moment.

The Seventh Doctor wore it on the lapel of his cream linen suit. (NA: White Darkness)