Earth's near-surface mineralogy has diversified over more than 4.5 b.y. from no more than a dozen preplanetary refractory mineral species (what have been referred to as "ur-minerals" by Hazen et al., 2008) to around 5,000 species (based on the list of minerals approved by the International Mineralogical Association; http://rruff.info/ima). This dramatic diversification is a consequence of three principal physical, chemical, and biological processes: element selection and concentration (primarily through planetary differentiation and fluidrock interactions); an expanded range of mineral-forming environments (including temperature, pressure, redox, and activities of volatile species); and the influence of the biosphere.