During medieval times, gemstones were believed to hold magical and even medicinal powers. The men and women who could afford such luxuries adorned themselves with brooches, rings, clasps and badges as a kind of talisman to ward off bad omens and spirits. At the top of the list are rubies which were believed to protect the wearer from poison, emeralds helped ward off madness and illness, and diamonds helped to make a person wise and protect against nightmares.
