Cal·ca·re·ous a.  Partaking of the nature of calcite or calcium carbonate; consisting of, or containing, calcium carbonate or carbonate of lime.
 Calcareous spar. Same as Calcite.

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 Cal·cite n.  Min. Calcium carbonate, or carbonate of lime. It is rhombohedral in its crystallization, and thus distinguished from aragonite.  It includes common limestone, chalk, and marble. Called also calc-spar and calcareous spar.
 Note: ☞ Argentine is a pearly lamellar variety; aphrite is foliated or chalklike; dogtooth spar, a form in acute rhombohedral or scalenohedral crystals; calc-sinter and calc-tufa are lose or porous varieties formed in caverns or wet grounds from calcareous deposits; agaric mineral is a soft, white friable variety of similar origin; stalaclite and stalagmite are varieties formed from the drillings in caverns. Iceland spar is a transparent variety, exhibiting the strong double refraction of the species, and hence is called doubly refracting spar.

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