Examples from the Web for calc-spar
It is harder than gypsum, but not so hard as calc-spar; flexible and elastic; spec.A Dictionary of Arts, Manufactures and Mines|Andrew Ure
It is considered by Dr. Feussner to be the most perfect prism capable of being prepared from calc-spar.
Its beds are from one to two feet thick, and much intersected by small veins of calc-spar.
Calc-spar will not supply the place of flint, nor lead the place of steel, in the production of fire by collision.Fragments of science, V. 1-2|John Tyndall
In calc-spar, as just stated, the ordinary ray is the most refracted.Six Lectures on Light|John Tyndall