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