The Zipf's Law is a rule of thumb applicable to numerous geological phenomena. It predicts how many entities of a certain size may be left in a sequence of decreasing size assuming the largest has been ascertained.
In general Zipf's Law is a good descripter of natural phenomena. Even if only descriptive, it gives the explorationist some insight in a mineral-resource assessment. (Merriam et al. 2004)
Sm/Sn = (n/m)**k
k = 1
Sm the size of item of rank m
Sn the size of item or rank n
k is a proper fraction
Costa, I.S.L., da Silva, G.F., & Vinícius Ferreira, M.(2019). Application of Zipf’s Law to Estimate Undiscovered Gold Endowment in the Quadrilátero Ferrífero Province, Brazil. Journal of the Geological Survey of Brazil, 2(3):165-72. https://doi.org/10.29396/jgsb.2019.v2.n3.3
Howarth, R.J., White, C.M. & Koch, G.S. (1980). On Zipf's Law applied to resource prediction. Transactions of the Institution of Mining and Metallurgy, Section A. Mining Technology, 89.
Merriam, D.F., Drew, L.J. & Schuenemeyer, J.H. (2004). Zipf’s Law: A Viable Geological Paradigm?. Natural Resources Research, 13(4). DOI: 10.1007/s11053-004-0134-5
Rowlands, N. J., & Sampey, D. (1977). Zipf’s Law–an aid to re�source inventory prediction in partially explored areas. Mathematical Geology, 9(4), 383–391.