The tornesel, tornesol, or tornese was a silver coin of Europe in the late Middle Ages and the early modern era. It took its name from the denier tournois, the denier of Tours. Marco Polo referred to the tornesel in recounts of his travels to East Asia when describing the currencies of the Yuan Empire. His descriptions were based on the conversion of 1 bezant = 20 groats = 133+1/ tornesel.
- Henry Yule. The Travels of Marco Polo: The Complete Yule-Cordier Edition. Third edition (1903), revised and updated by Henri Cordier. Plain Label Books. p. 1226-27. (ISBN 1603036156)