Used with permission of Maiken Naylor, University at Buffalo, Buffalo, NY, USA, http://ublib.buffalo.edu/libraries/units/sel/exhibits/stamps

Marie Sklodowska Curie (1867-1934) was a double Nobel Prize winner, jointly with her husband Pierre (1859-1906) and Becquerel for the discovery of radiactivity in 1903, and by herself in 1911 for the discovery and isolation of radium. One of many stamps issued by her native Poland just emerging from the ravages of World War II dispenses with perforations. The Monaco stamp shows the cumbersome apparatus used to separate the raw ores from which radium was finally obtained. She is also shown with a glowing bowl containing her discovery, and again holding a laboratory sample. Together, the Curies appear on a stamp of Central Africa with what appears to be a very active molecular cluster. The word "radioactive" was first used by Marie Curie to describe her observations, as published in Comptes Rendus.

Pierre Curie, besides his work in radioactivity, was the discoverer of piezoelectricity. He also observed that permanent magnets lose their magnetic properties when heated above a critical temperature, which is called the Curie temperature.