The Sandstone Greenstone Belt is an exploration-immature, regolith-covered, approximately 1000 sq. km belt, in the Southern Cross Domain of the Yilgarn Craton. In order to estimate potential endowment, historical gold production and deposit resource estimates are required to be quantitatively analysed for calculation of natural and residual gold endowment. The total residual gold endowment within the oxide zone of the Sandstone Greenstone Belt is estimated, by application of a Zipf's law statistical assessment, to be 2.3 Moz. This mineralisation is most likely contained in extensions of known deposits and several undiscovered deposits. The fresh rock of the Sandstone Greenstone Belt remains poorly explored. However, a conceptual endowment estimate can be made, based on a minerals system comparison between the exploration-immature Sandstone Greenstone Belt and the well-explored, geologically-similar Agnew Greenstone Belt, 100 km to the east. It is possible that natural endowment at Sandstone could total 21.3 Moz, with nine undiscovered deposits of >0.5 Moz. Application of such a minerals-system integrated endowment assessment represents an effective motivator to embark on a well-resourced gold exploration campaign in the Sandstone Greenstone Belt, a currently immature exploration search space.