allotropy

noun

al·lot·ro·py | \ ə-ˈlä-trə-pē

plural allotropies

Definition of allotropy

: the existence of a substance and especially an element in two or more different forms (as of crystals) usually in the same phase

History and Etymology for allotropy

borrowed from German Allotropie, borrowed from Swedish allotropi, from Late Greek allótropos, taken to mean "of a different character" (from allo- allo- + -tropos, adjective derivative from trópos "turn, direction, manner, character") + -i -y entry 2 — more at trope

Note: The Swedish noun allotropi was introduced by Jakob berzelius in Årsberättelse om framstegen i fysik och kemi afgiven den 31 mars 1840, andra delen (Stockholm, 1840), p. 14 (translated into German as Jahres-Bericht über die Fortschritte der physischen Wissenschaften von Jacob Berzelius, eingereicht an die schwedische Akademie der Wissenschaften den 31. März 1840, 20. Jahrgang, Tübingen, 1841). As the source of the word Berzelius adduces Greek allótropos, defined as "af olika beskaffenhet" ("of a different character"); he may have taken it from Passow's Handwörterbuch der griechischen Sprache (4. Ausgabe, Leipzig, 1831), where it is translated "andersartig, veränderlich" ("different, variable"), without textual attestation. Liddell and Scott's A Greek-English Lexicon shows limited Late Greek evidence for the word, defined as "strange."