"An' they don't CALC worth a cent.
"The Son of his Father"
Ridgwell Cullum
It attains a thickness of about 100 feet, and though very different in age, much resembles in mineral character the "London clay," containing, like it, septaria or concretions of argillaceous limestone traversed by cracks in the interior, which are filled with CALC-spar.
"The Student's Elements of Geology"
Sir Charles Lyell
The statement that a crystal of CALC-spar consists of carbonate of lime, is quite true, if we only mean that, by appropriate processes, it may be resolved into carbonic acid and quicklime.
"Autobiography and Selected Essays"
Thomas Henry Huxley