On the Origin of the Term 'Sphärolith': Abraham Gottlob Werner as the Coiner of a Fundamental Mineralogical Concept

The term ‘spherulite’ (German: Sphärolith) is today widely employed in petrology, mineralogy, and polymer physics to denote spherical or near-spherical bodies with radiate internal structure. Current reference works, including encyclopaedias and databases, attribute the term solely to Greek etymology (sphaira + lithos) and do not identify a coiner. This short communication presents documentary evidence—drawn from a digitally accessible primary source—demonstrating that the term was coined by Abraham Gottlob Werner (1749–1817) and applied by him to small spherical bodies occurring in Hungarian perlite porphyries. The evidence is a printed entry in J. R. Zappe’s Mineralogisches HandLexicon (Vienna: C. F. Beck, 1817, vol. 3, p. 318), which explicitly states: “eine neue Benennung, welche Werner den in den hungarischen Perlstein-Porphyren vorkommenden kleinen Kugeln gegeben hat” (‘a new name given by Werner to the small spheres occurring in the Hungarian perlite porphyries’). The attribution of this foundational term to Werner constitutes a recoverable fact of the history of mineralogy that has been absent from the modern scientific literature.