Zinc
Five isotopes of zinc are found in nature. 64Zn is the most common isotope, with 48.63% of naturally occurring Zinc. This isotope has a half-life of 4.3x1018 years. This is so long, that its radioactivity can be ignored. Similarly,  (0.6%), with a half life of 1.3x1016 years  is usually considered to not be radioactive. The other isotopes found in nature are  (28%),  (4%) and  (19%).