What is the nature of chert and flint nodules?
"Geology"
James Geikie
From the bridge upwards the rocks are all gneiss, alternating with chert and quartz.
"Himalayan Journals V2."
J. D. Hooker
We must imagine that many strata of limestone, chert, and other rocks which are now brittle, were pliant when bent into their present position.
"The Student's Elements of Geology"
Sir Charles Lyell