Historical natural kinds and mineralogy: Systematizing contingency in the context of necessity

Abstract

The advancement of science depends upon developing classification protocols that systematize natural objects and phenomena into "natural kinds"-categorizations that are conjectured to represent genuine divisions in nature by virtue of playing central roles in the articulation of successful scientific theories. In the physical sciences, theoretically powerful classification systems, such as the periodic table, are typically time independent. Similarly, the standard classification of mineral species by the International Mineralogical Association's Commission on New Minerals, Nomenclature, and Classification relies on idealized chemical composition and crystal structure, which are time-independent attributes selected on the basis of theoretical considerations from chemical theory and solid-state physics. However, when considering mineral kinds in the historical context of planetary evolution, a different, time-dependent classification scheme is warranted. We propose an "evolutionary" system of mineral classification based on recognition of the role played by minerals in the origin and development of planetary systems. Lacking a comprehensive theory of chemical evolution capable of explaining the time-dependent pattern of chemical complexification exhibited by our universe, we recommend a bootstrapping approach to mineral classification based on observations of geological field studies, astronomical observations, laboratory experiments, and analyses of natural samples and their environments. This approach holds the potential to elucidate underlying universal principles of cosmic chemical complexification.

Keywords: classification; cosmic evolution; mineral evolution; mineralogy; natural kinds.

Fig. 1.

The “pyroxene quadrilateral,” illustrating chemical compositions of pyroxenes with idealized compositions represented by (Mg,Fe,Ca)₂Si₂O₆. Most natural pyroxenes do not lie near one of the corners of this quadrilateral and are given the names “augite” or “pigeonite.”