t 



382 University of California Publications. [Geology 



data (philipstadite, hudsonite, hastingsite, barkevikite, etc.) 

 which we have seem to show that the rule is quite general. 



If this suggestion holds, then the making of new species in a 

 type because the pleochroism and angle of extinction differ more 

 or less, is worse than unnecessary, for we have seen clearly in the 

 glaucamphiboles that the replacing of A1 2 3 by a small quantity 

 of Fe 2 ;i brings about a noticeable variation in these two prop- 

 erties and also in the etch-figures. There would be an unlimited 

 number of species in any series. 



In order to make the nomenclature more simple and natural, 

 I should like to propose the following classification : 



Plane Optic 



Al20 3 Fe20 3 of 2 V char- Formula* 1 



axes acter 



Pargasite 14—11 0—3 —25° (010) 50°— 60° + S+0 to 1G+4 to 3K (+Fe) 



Karinthine 14-12 0—2 —17° to —28° (010) very large — S+0 to 1G+4 to 3K 



Soretite*- 10 —17° to (—28°) (010) 80°— 90° - S + l to 2G+3 to 2K 



Barkevikite* 3 1G-10 0-4 —12° to (—25°) (010) ilarge - S+3G+K 



Noralite* 4 12 1 ? ? — S+3 to 4G+1 to OK 



"Where: S = Syntagmatite molecule, = (AlFe 2 ) _(CaNa 2 ) 3 Si 3 12 , Gr = 

 grunerite mol., = FeSiO.,; K = kupferite mol., = MgSi0 3 . 



* 2 Under soretite are to be included the hornblendes corresponding to the 

 analyses XI, XII, XIII, XCI, CXXIII, CXXiy CXCVIII CCXL, etc., in 

 Hintze's Manual; further, philipstadite (also CXXVI, CXLVIII, CXLVI, 

 etc.) and camsigradite which is a Mn-containing philipstadite. See for 

 details, Hintze, Handbueh der Mineralogie, II. 



* 3 Under barkevikite could be included the hornblendes corresponding to 

 the analyses CCL, CCLII (see Table II, No. XI and XII), etc., in Hintze's 

 book. Also hudsonite and hastingsite, (Tab. Ill), although they have very 

 pronounced pleochroism in blue; I may remark that the brown barkevikites 

 are not only titaniferous but are also very poor in Fe 2 3 . 



**Under noralite (Dana) must be included also the hornblendes corre- 

 sponding to CCXLVI, CCLII, etc., in Hintze's book. See V and III in 

 Tab. III.) 



Perhaps to karinthine, soretite, or barkevikite corresponds a 

 series from aluminous to ferruginous amphiboles parallel to that 

 of glaucophane rhodusite, these known members being the most 

 aluminous.* As we can see in the accompany table (for details 

 see Hintze's manual, Rosenbusch 's, etc.), analyses of karinthine 

 amphiboles rich in Fe'" are quite unknown. Very probably it is 

 to this unknown catgeory of karinthines that the green or bluish 



* I may remark that in the riebeckite series the members rich in Fe'" are 

 almost the only ones known; that of Jaeobdeal analysed by L. Mrazek 

 (Table II., No. VI) has 7% A1 2 3 (+Zr0 2 , etc.) 



