A sequence of common silicate minerals, laid out in the order of their susceptibility to chemical weathering. A well-known series was suggested by S. S. Goldich in 1938 and runs from quartz (most resistant), through muscovite, alkali feldspar, biotite, the plagioclase feldspars, and olivine (least resistant). This sequence is the reverse of Bowen’s reaction series, which ranks minerals in the order of their crystallization from a melt. An absolute scale of weathering susceptibility is unlikely to be achieved, partly because of variations in environmental conditions.