How rare is astatine?

Written and fact-checked by

The Editors of Encyclopaedia Britannica

Because of the short half-lives of astatine isotopes, only very small quantities have been available for study; some sources argue that less than 1 gram is present in Earth’s crustat any given time. In addition, solutions involving astatine are so dilute that the presence of impurities pose serious concerns in researching this chemical element.