Definition of pyrophyllite in US English:

pyrophyllite

(also pyrophillite, pyrophilite)

noun

  • An aluminosilicate mineral resembling talc, occurring as white or pale-coloured foliated masses which exfoliate when heated.

Origin

Mid 19th century; earliest use found in Edinburgh New Philosophical Journal. From pyro- + ancient Greek ϕύλλον leaf + -ite, after German Pyrophyllit, so called on account of its exfoliation when heated.

Pronunciation

pyrophyllite

/ˌpʌɪrə(ʊ)ˈfɪlʌɪt/