The physico-chemical implications of cementitious stabilisation across a range of soil geochemical conditions have been addressed to rationalise the current state of practice. The processes that influence the gain in soil characteristics include the short-term flocculation of clay particles that stabilises the expansive nature of moisture-sensitive soils, and the occurrence of pozzolanic reaction to give cementitious products. The proposed approach to slurry design is based on assessing the potential for these two processes in the soil chemistry and mineralogy and matching a complementary cementitious additive type and concentration. Ten soils have been collected and assessed using the Unified Soil Classification System and the Great Soil Group Classification System. The former classification system is used to express the plasticity characteristics of the soil deposit. The latter system is used by agricultural scientists to express the profile development of soil deposits, and provides a convenient source for gaining an appreciation of site geochemistry without deferring to expensive laboratory tests. The two systems can be used to determine an appropriate slurry composition to affect a desired geotechnical response. This will improve the efficiency of the stabilisation routine.