allophane

noun

al·​lo·​phane ˈa-lə-ˌfān 

: an amorphous translucent mineral of various colors often occurring in incrustations or stalactite forms and consisting of a hydrous aluminum silicate

Word History

Etymology

borrowed from German Allophan, borrowed from Late Greek allophanḗs "appearing otherwise," from Greek allo- allo- + -phanēs -phane

Note: The name Allophan was introduced by the German chemist Friedrich Stromeyer (1776-1835) and the mineralogist Johann Friedrich Ludwig Hausmann (1782-1859) in "Bemerkungen über den Allophan," Annalen der Physik, Band 54 (1816), pp. 120-37. The authors account for the name at the end of the article: "These components of the mineral cannot be easily surmised from its appearance. In order to point this out we suggest as its name allophane." ("Die Aeussere des Fossils wird diese Bestandtheile nicht leicht vermuthen lassen. Um hierauf hinzudeuten, bringen wir zur Bezeichnung desselben den Namen Allophan in Vorschlag.") The rare Greek word allophanḗs was most likely chosen from a dictionary; it is glossed "anders erscheinend" ("appearing to be different") in Johann Gottlob Schneider's Kritisches griechisch-deutsches Wörterbuch (2. Auflage, 1805).

First Known Use

1817, in the meaning defined above