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PRIMARY LIMESTONE. 



SYNOPSIS OF PRIMARY LIMESTONE. 



FIRST DIVISION. 

 Simple. 



A. Crystalline. 



a. Very large grained, with straight lamellce. 



b. The same, with the lamellae curved. 



c. Large grained, and the crystals appearing 



to have compressed each other, as in 

 coccolite. 



d. Of a middle sized grain marble of Paros, 



&c. 



e. Finely granular, saccharine, and firm or 



loose : marble of Carrara. 



f. Finely granular and compacted, becoming 



splintery. 



g. The crystals so disposed, in consequence 



of a common polarity, that the fock has 

 an imperfect schistose structure. In 

 these cases it often appears, on a super- 

 ficial view, to contain mica. 



B. Compact. 



a. Splintery; but with a rough, somewhat 



granular fracture, passing into the last 

 named variety. 



b. Flat splintery ; smooth. 



c. Splintery and conchoidal. 



