pyrophyllite

noun

py·​ro·​phyl·​lite ˌpī-rō-ˈfi-ˌlīt  pī-ˈrä-fə-ˌlīt 

: a soft usually white or greenish mineral that is a hydrous aluminum silicate, resembles talc, occurs in a foliated form or in compact masses, and is used especially in ceramic wares

Word History

Etymology

German Pyrophyllit, from Greek pyr- + phyllon leaf — more at blade

First Known Use

1830, in the meaning defined above