phyllite
(ˈfɪlaɪt)
[f. Gr. ϕύλλον a leaf + -ite1.]
1. Min. a. A species of magnesia-mica, occurring in small scales in argillaceous schist or slate. b. A rock consisting of an argillaceous schist or slate containing scales or flakes of mica.
See A. R. Hunt Notes on Petrolog. Nomencl. in Geol. Mag. Jan. 1896, 31–35.
| a. 1828 Thomson in Ann. N.Y. Lyceum Nat. Hist. III. 47 Phyllite..will probably constitute a new species. 1862 Dana Man. Geol. vi. 77 The ottrelite has been called phyllite. 1892 ― Min. (ed. 6) 642. |
| b. 1881 Rep. Geol. Expl. N. Zealand 128 A series of less altered rocks (phyllites) form the northern part of the Eyrie Mountains. 1886 Geikie Class-bk. Geol. 223 By increase of its mica-flakes a clay-slate passes into a phyllite. 1892 Teall in Proc. Somerset Archæol. Soc. 211 A schistose rock intermediate between a phyllite and a mica-schist. |
2. Geol. A general name for a fossil leaf. ?
Obs.| 1843 W. Humble Dict. Geol. & Min., Phyllite, a pertrified leaf. |
Hence
phyllitic (
fɪˈlɪtɪk)
a., consisting of or having the character of phyllite.
| 1888 Nature 8 Nov. 31/1 Generally the slates are schistose, phyllitic, and chiastolitic. |