i 4: 4 



Outlines of the Mineralogy and Geology 



The fragments are indeterminately angular, and not particu- 

 larly sharp edged. ^^ 



It phosphoresces by friction^ and when projected in powder on 

 a heated iron« 



Its specifick gravity is about 3.874. 



Chymical Character 

 It is infusible before the blowpipe. 



Geological Situation and Locality, 

 It occurs in a bed in Micaceous Schistus at Chelmsford 



Use, 



It is employed for various purposes, after being deprived of 

 its water and carbonic acid, by burning. 



Subspecies III. — Fibrous Limestone. 



I 



Fibrous Limestone, Cleaveland^ p. 156. Common Fibrous Limestone, Jam«- 



F 



sonf Yol. I. p. 497. Fibrous Carbonate of Lime, Aihin, p. 175. 



External Characters, 



Its colour is snow white. 



Its lustre is faintly glistening and silky. 



4 



It is translucent at the edges. 



It is amorphous. 

 It is very soft. 



The cross fracture is fine splintery, 



the longitudinal fracture 



is fine straisiht fibrous. 



o 



It is easily frangible. 



The fragments are splintery. 



Its specifick gravity is about i.941. 



