Isotopes of gold

Gold (Au) has a few naturally occurring isotopes, the most common of which is gold-197 (^197Au). This isotope is stable and makes up nearly all naturally occurring gold. Gold-197 has an atomic mass of approximately 196.96657 u. In addition to ^197Au, there are several radioactive isotopes of gold, though they are not found in nature and are typically produced in laboratories or through nuclear reactions.