Copyright © Mineralogical Society of America Overview and General Concepts

Of the eighty-three naturally occurring elements that are not radioactive or have half lives long enough to be considered stable (≥109 yrs), nearly three-quarters have two or more isotopes. Variations in the isotopic ratios of a number of these elements, including H, C, N, O, and S, provide the foundation for the fi eld of stable isotope geochemistry. Investigation