132 Washington — Plauenal Monzonose (Syenite), 



Analyses of syenite from the Plauenscher Grund. 





I 



II 



III 



IV 



V 



VI 



VII 



VIII 



Si0 2 



59-83 



60-02 



62-49 



58-70 







60-60 



1-010 



Al 2 3 



16*85 



16-66 



16-49 



17-09 







1679 



•165 



Fe 2 3 



... 



7-21 



2-36 



3-17 







2-77 



•017 



FeO 



V-01 







2-04 



2-29 







2-17 



•031 



MgO 



2-61 



2-51 



1-87 



2-41 







2-14 



•054 



CaO 



4-43 



3-59 



4*23 



4-71 







4-47 



•080 



Na 2 



2*44 



2-41 



4-38 



4-38 



4-34 



4-49 



4-40 



•071 



K 2 



6-57 



6-50 



4-65 



4-35 



4-33 



4-93 



4-57 



•049 



H 2 + \ 

 H 2 0- ) 



- 1-29 



1-10 



j 0*32 

 j 0-28 



0-89 







0-61 





0-23 







025 





CO, 







. . . 



none 



none 







none 





Ti0 2 









0-85 



0-95 







0-90 



•on 



Zr() 2 







none 









none 





p 2 o 5 



..... 







0-32 



0-23 







0-28 



•002 



so 3 



. _ . 







none 









none 





s 











none 











none 





MnO 



n.d. 



n.d. 



n.d. 



n.d. 







n.d. 





BaO 











0-15 











0-15 





SrO 



- -• 



100-00 



trace 











trace 



100-10 





101-03 



100-43 



99-40 





Sp. Gr. 



2-730 

















I. 



F. Zirkel, Pogg. Am 



i. cxxii, 



1864, p. 



622. 







II. 



Griffith, Che 



m. News, xlvii, 



1882, p. 



170 



(cf. Bro 



gger, 





op. 



cit., p. 



30). 













III. 



Specimen of 



H. S. Washington. 









IV. 



Specimen from W. Cross. 











V. 



Speci 



men from L. V 



. Pirsson. 









VI. 



Specimen fr< 



Dm J. F. 



Kemp. 











VII. 



Aver 



age of 



Ill, IV, 



V and VI. 









VIII. 



Molecular ratios of 



VII. 











plete, especially as regards the iron oxides, while the total of 

 II (exactly IOD'00) gives rise to some uneasiness. 



They both resemble III and IV in the figures for silica, 

 alumina, magnesia and lime, but differ much in those for the 

 oxides of iron and the alkalies, though the total amount of 

 these last is about the same in all. It may be noted, however, 

 that the specimens analyzed by Zirkel and Griffith and that of 

 Cross are evidently slightly more femic than mine. This is 

 shown by the lower silica and higher iron oxides, magnesia 

 and lime, as well as by the alumina when it is remembered 

 that the Al 2 3 of I and II include the Ti0 2 and P 2 5 of the 

 rock.* 



*The Si0 2 will also include some of the Ti0 2 and possibly a little Fe 2 3 , 

 etc., if it was not checked as to purity by evaporation with hydrofluoric and 

 sulphuric acids. It may be noted that the unchecked silica in IV amounted 

 to 59-45 per cent. 



