Four factors contribute to the roles played by chance and necessity in determining mineral distribution and diversity at or near the surfaces of terrestrial planets: (1) crystal chemical characteristics; (2) mineral stability ranges; (3) the probability of occurrence for rare minerals; and (4) stellar and planetary stoichiometries in extrasolar systems.The most abundant elements generally have the largest numbers of mineral species, as modeled by relationships for Earth's upper continental crust (E) and the Moon (M), respectively: LogðN E Þ ¼ 0:22 LogðC E Þ þ 1:70 ðR 2 ¼ 0:34Þð4861 minerals; 72 elementsÞ LogðN M Þ ¼ 0:19 LogðC M Þ þ 0:23 ðR 2 ¼ 0mineral species await discovery or could have occurred at some point in Earth's history, only to be subsequently lost by burial, erosion, or subduction-i.e., much of Earth's mineral diversity associated with rare species results from stochastic processes.Measurements of stellar stoichiometry reveal that stars can differ significantly from the Sun in relative abundances of rock-forming elements, which implies that bulk compositions of some extrasolar Earth-like planets likely differ significantly from those of Earth, particularly if the fractionation processes in evolving stellar nebulas and planetary differentiation are factored in. Comparison of Earth's upper continental crust and the Moon shows that differences in element ratios are reflected in ratios of mineral species containing these elements.In summary, although deterministic factors control the distribution of the most common rock-forming minerals in Earth's upper continental crust and on the Moon, stochastic processes play a significant role in the diversity of less common minerals. Were Earth's history to be replayed, and thousands of mineral species discovered and characterized anew, it is probable that many of those minerals would differ from species known today.

A population model is introduced to describe the mineral species frequency distribution. Mineral species coupled with their localities conform to a large number of rare events (LNRE) distribution: 100 common mineral species occur at more than 1,000 localities, whereas 34 % of the approved 4,831 mineral species are found at only one or two localities. LNRE models formulated in terms of a structural type distribution allow the estimation of Earth's undiscovered mineralogical diversity and the prediction of the percentage of observed mineral species that would differ if Earth's history were replayed.

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