pyrophyllite

[ pahy-ruh-fil-ahyt, pahy-rof-uh-lahyt ]

noun

1. Mineralogy. a phyllosilicate, AlSi 2 O 5 (OH), usually having a white or greenish color, and occurring in either foliated or compact masses, the latter variety being used like soapstone.

pyrophyllite

/ ˌpaɪrəʊˈfɪlaɪt /

noun

1. 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

Word History and Origins

Origin of pyrophyllite¹

First recorded in 1820–30, pyrophyllite is from the German word Pyrophyllit; so called because it exfoliates when heated. See pyro-, -phyll, -ite ¹

Example Sentences

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

From Project Gutenberg