Argillite
[ɑ:dʒilait]
Definition
(noun.) a sedimentary rock differing from shale in being bound by silica and from slate in having no slate cleavages.
Edited by Lelia--From WordNet
Definition
(n.) Argillaceous schist or slate; clay slate. Its colors is bluish or blackish gray, sometimes greenish gray, brownish red, etc.
Edited by Candice