'Chert' definitions:

Definition of 'chert'

(from WordNet)
noun
Variety of silica containing microcrystalline quartz

Definition of 'Chert'

From: GCIDE
  • Chert \Chert\ (ch[~e]rt), n. [Ir. ceart stone, perh. akin to E. crag.] (Min.) An impure, massive, flintlike quartz or hornstone, of a dull color. [1913 Webster]

Definition of 'chert'

From: GCIDE
  • Hornstone \Horn"stone`\, n. (Min.) A siliceous stone, a variety of quartz, closely resembling flint, but more brittle; -- called also chert. [1913 Webster]