pyrophyllite

American  

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

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.

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pyrophyllite British  

/ 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

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Etymology

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, -ite ¹

Example Sentences

Pyrite, 100, 107-109, 307, 386, 397 Pyrophyllite, 299 Quartz, as geologic thermometer, 38 geologic occurrence, 16, 38-39, 43, 45, 47, 168-169, 196 production and use, 84, 267, 269 Quartzite, 84, 91 Quebec, Canada, asbestos, 270-272 magnesite, 193 mica, 286 Quebec, laws relating to ownership of mineral resources, 344 Queensland, Australia, arsenic, 250 Quicksilver ores.

From Project Gutenberg

The following minerals, according to Griffin, produce beads with soda, but do not fuse when heated alone: quartz, agalmatolyte, dioptase, hisingerite, sideroschilosite, leucite, rutile, pyrophyllite, wolckonskoite.

From Project Gutenberg