PHYSIOGRAPHY. 



According to Dr G. ROSE, it consists of 



Silica 44*49. 



Alumina 34*46. 



Oxide of Iron 074. 



Lime 15-68. 



Magnesia 5*26. 



Before the blowpipe it comports itself nearly like prismatic 

 Feld-spar, Albite, and Labradorite, only that with soda it 

 does not give a clear glass. It is entirely decomposed by 

 concentrated muriatic acid. 



The only locality of Anorthite is Mount Vesuvius ; it is 

 found lining cavities in limestone, along with a green va- 

 riety of paratomous Augite-spar. 



APHRITE. 



Aphrite. JAM. Syst. Vol. II. p. 543. Man. p. 48. 

 Aphrite. PHILL. p. 150. 



Prismatic. Cleavage monotomous, very distinct. 



Massive : composition granular, sometimes scaly, 



sometimes not coherent. 

 Lustre pearly upon the faces of cleavage. Colour 



white. Streak white. Opake. 

 Sectile. Feels fine, not greasy. Soils a little. 



Hardness = 0-5 ... 1-0. Sp. Gr. = 2-533. 



It effervesces violently with nitric acid, and is completely 

 dissolved. The friable varieties readily absorb water, du- 

 ring which they give a crackling noise. According to 

 BUCHOLZ, it consists of 



Lime 51-500. 



Silica 5-715. 



Oxide of Iron 3-285. 



Carbonic Acid 39-000. 



Water 1-000. 



It occurs at Rubiz near Gera in Saxony, upon the Meiss- 



