Washington — Pyroxenite and Hornblendite in Brazil. 85 



closest analogues being given. Like the hornblende, it is 

 remarkable for its high manganese, and the amount of chromium 

 is also notable. 



Table III. 



A B C D 



Si0 2 ._. 51-23 51-83 51-76 47'29 



Al,6 3 6-17 7-98 6-05 16-93 



Fe 2 3 ._ 1*96 1-48 1*64 1'58 



Feb 6-95 8-28 8*01 2'67 



MgO 26-52 24*10 27-14 21-01 



CaO 4-03 5-26 3*12 8'56 



Na,0 ._ 0-29 0-35 0*79 1*17 



K 2 0-12 0-06 0-32 0'39 



H 2 + .._ 0-14 0-29 0-82 0'29 



H,0- 0-10 



Ti0 2 .__ 0-27 0-29 



P 2 5 none 0-09 0-07 



S _ 0-41 0-17 



Cr 2 3 . 0-31 0-31 



MnO _ 1-46 trace 



NiO 0-11 _. 



BaO _ none 



CuO 0-21 



100-17 100-43 99*89 99*89 



A. Hornblende-hypersthenite (IV".l (])2 .l.(l)2. Near Maracas, 

 Bahia, Brazil. H. S. Washington, analyst. 



B. Hornblende-hypersthenite (IV.l. (l)2 . 1.2). Between Meadow 

 and Grass Creeks, Montana. L. G. Eakins, analyst. G. P. Mer- 

 rill, Proc. IT. S. Nat. Mus., xvii, p. 658, 1895. 



C. Bronzite rock (IV.1. 4 .1.(1)2). Radau, Hartz Mountains. 

 Eyme, analyst. O. H. Erdmannsdoerfer, Jb. Pr. G. L-A., xxv, 

 (1904), p. 471, 1907. 



D. Ariegite, Escourgeat, Ariego, Pyrenees. Pisani, analyst. 

 A. Lacroix, C. R., cxxxii, p. 359, 1901. 



The analysis of ariegite will be referred to later. 

 Classification. — The norms of these three rocks are as 

 follows : 



ABC 



Or 0-56 0-56 1'67 



Ab 2-62 3-14 6*81 



An v 15-01 19-74 11-95 



Di 3-73 5-10 2-62 



Hy.._ 62-89 60-48 57'90 



OL 10-86 8-70 15-74 



Mt 2-78 2-09 2-32 



II 46 0-61 



