PHYSIOGRAPHY. 



Arragonite. 



39 



Lustre vitreous. Color black. Opake. 

 Hardness inferior to Hornblende. Sp. gr. =3'44. 



1. It melts easily before the blow-pipe into a black globule. With 

 borax, it gives a glass colored by iron ; with salt of phosphorus, likewise, 

 but paler, and becoming colorless on cooling, whilst a dark grey silica- 

 skeleton remains undissolved. 



2. It occurs along with black Augite and black Sodalite in Greenland, 

 and has generally been considered as a ferruginous variety of Horn- 

 blende, from which, however, its brilliant cleavages, the inclination of 

 its lateral faces and inferior hardness, seem sufficiently to distinguish it 

 as a new species. 



The mineral generally taken for a variety of Hornblende in a porphy- 

 ritic trap from Plymouth, (Vt.) appears to agree with the above descrip- 

 tion. 



ARRAGONITE. Prismatic Lime Haloide. 

 MOHS. 



Primary form. Right rhombic prism. M on M' = 

 116 10'. 



Secondary forms. 



Fig. 43. Fig. 44. 



M on cl 

 Mon M 7 

 M'onA 

 h on cl 

 cl on cl 

 M on b 

 cl on c2 

 cl on c3 

 cl on b 

 b on b 



1 QQO 1 Q/ "^ Bilin, Bohemia. 



116 10 I 



121 38 ^ PHILLIPS. 



125 55 



108 18 J 



144 oon 



150 30 



141 00 VPHILLIPS. 



136 30 I 



129 33 J 



