This chapter, titled "Compilation of Stable Isotope Fractionation Factors of Geochemical Interest," is part of the sixth edition of "Data of Geochemistry" and is authored by Irving Friedman and James R. O'Neil. It compiles and presents stable isotope fractionation factors for hydrogen, carbon, oxygen, and sulfur, plotting these factors as a function of temperature in degrees Celsius. The chapter includes discussions on terminology, the problems of isotope standards, and equations relating various standards used for reporting oxygen-18 values. It also provides a comprehensive list of references and detailed illustrations, including graphs showing fractionation factors for different isotopes and systems. The chapter aims to serve as a valuable resource for researchers in geochemistry, meteorology, oceanography, and other scientific fields, providing a single reference for stable isotope fractionation factors of geologic interest.This chapter, titled "Compilation of Stable Isotope Fractionation Factors of Geochemical Interest," is part of the sixth edition of "Data of Geochemistry" and is authored by Irving Friedman and James R. O'Neil. It compiles and presents stable isotope fractionation factors for hydrogen, carbon, oxygen, and sulfur, plotting these factors as a function of temperature in degrees Celsius. The chapter includes discussions on terminology, the problems of isotope standards, and equations relating various standards used for reporting oxygen-18 values. It also provides a comprehensive list of references and detailed illustrations, including graphs showing fractionation factors for different isotopes and systems. The chapter aims to serve as a valuable resource for researchers in geochemistry, meteorology, oceanography, and other scientific fields, providing a single reference for stable isotope fractionation factors of geologic interest.