Word Study
chert
CIDE DICTIONARY
chert, n. [Ir. ceart stone, perh. akin to E. crag.].
An impure, massive, flintlike quartz or hornstone, of a dull color. [1913 Webster]
OXFORD DICTIONARY
chert, n. a flintlike form of quartz composed of chalcedony.
Derivative
cherty adj.
Etymology
17th c.: orig. unkn.
For further exploring for "chert" in Webster Dictionary Online