The Curies Announce the Discovery of Radium
Institut de France, Rue de Seine, Quartier de Saint-Germain-des-Prés, 6th Arrondissement, Paris, Ile-de-France, Metropolitan France, 75006, France
French Academy of Sciences
CONFIRMED88% CONFIDENCEWikipedia's[2] Radium article dates both steps: "Radium was discovered by Marie Sklodowska-Curie and her husband Pierre Curie on 21 December 1898 in a uraninite (pitchblende) sample from Jachymov" and "The Curies announced their discovery to the French Academy of Sciences on 26 December 1898". The pin is the announcement, the public event of the two.
Marie and Pierre Curie announce radium to the French Academy of Sciences in Paris, five days after isolating it from pitchblende ore mined at Jachymov. It is the second element they identify that year, after polonium.
Cavendish Laboratory