pyrophyllite

[ pahy-ruh-fil-ahyt, pahy-rof-uh-lahyt ]
/ ˌpaɪ rəˈfɪl aɪt, paɪˈrɒf əˌlaɪt /

noun

Mineralogy. a phyllosilicate, AlSi2O5(OH), usually having a white or greenish color, and occurring in either foliated or compact masses, the latter variety being used like soapstone.

Origin of pyrophyllite

First recorded in 1820–30, pyrophyllite is from the German word Pyrophyllit; so called because it exfoliates when heated. See pyro-, -phyll, -ite1

Example sentences from the Web for pyrophyllite

  • Pyrophyllite (hydrated aluminum silicate) resembles talc in some of its properties and is used in much the same way.

British Dictionary definitions for pyrophyllite

pyrophyllite
/ (ˌpaɪrəʊˈfɪlaɪt) /

noun

a white, silvery, or green micaceous mineral that consists of hydrated aluminium silicate in monoclinic crystalline form and occurs in metamorphic rocks. Formula: Al 2 Si 4 O 10 (OH) 2