112 PHYSIOGRAPHY. 



Calcareous Spar. 



2-7284, white cleavage crystals, at Zaukerode near Dresden. 

 2-7300, a crystal from Northumberland. 



The most of these varieties are too imperfectly cleavable to admit of 

 accurate measurement. 



vii. Melinous Carbon- Spar. BREITHAUPT. 

 P on P = 105 17'. 



Cleavage perfectly obtained parallel with the primary rhomboid. 

 Hardness (scale of BREITHAUPT) = 4 . . . 4-25. 

 Sp.gr. =2-6958, honey yellow, cleavage crystals from Neu- 



dorf at Borna. 



2-6968, from Mont Martre near Paris. 



It is found in green-sand and in' planerkalkstein in Saxony. It also 

 occurs at Cotta, at Naundorf in Borna, and again on the lower portions 

 of Zehista in the region of Pirna. Under similar circumstances at Dux 

 in Bohemia. 



viii. Diastatic Carbon-Spar. BREITHAUPT. 

 PonP=105 43>. 



Cleavage parallel with primary rhomboid perfect. 

 Hardness (scale of BREITHAUPT) =4. . .4-25. 

 Sp.gr. =2 7698, massive variety from Seegen Gottes, Freiberg. 

 2-7758, cleavage crystals from Habacht, Freiberg. 

 2'7870 common fibrous limestone, from Adam Heber 

 in Schneeberg. 



ix. Plumbo- Calcite. TURNER. Carbonate of Lime and Lead. 

 P on P = 104 53' 30". 

 Hardness. It is scratched by Iceland Spar. 

 Surface of crystals slightly rounded. 

 Lustre pearly. Sp.gr. =282. 

 Massive and opake. 



Heated in a platina crucible, or in a glass tube, it decrepitates, and af- 

 ter some time assumes a brownish, or pale reddish tint. It consists of 

 Carbonate of lime . . . . 92-2 

 Lead .... 7-8 



x. Prunnerite. ESMARK. 



The violet blue variety of Calcareous Spar, occurring with Apophyl- 

 lite in the Island of Hestoe, one of the Faroes, and hitherto arranged as a 

 variety of cuboidal Calcareous Spar, has been established into a distinct 



