89 



Molecular ratios. 



SlOo 53,61 0,8933 



Fe.,0^ 11,24 0,1414 I 2 



Al^O.^ 4,27 0,0838 I 



FeO 4,13 0,0574 ) 



MtlO 0,64 0,0090 1 3 



MffO 10,16 0,2540 J 



Na^O 8,55 0,1379 1 



K^O 7,80 0,0929 / 



100,40 



The formula deduced from this analysis is 



{Al, Fe], (Mg, Fe, Мп), (Na^, К,), Si, О,,, 

 which may be written structurally as follows. 

 Na-SiO, ^j 



3 



I 

 ■SiO 



Al~SiO.,—Na 



Al — SiO.^ — Na 



Consequently, the mineral is a metasilicate, being nearest 

 to aegirine or arfvedsonite in composition, whereas on account 

 of its other characters it might be referred to the mica, the 

 chlorite, or, possibly, the pyrosmalite group. 



Spodiophyllite has only been found at the locality No. о on 

 Narsarsuk. The mineral occurred very sparingly on a few spe- 

 cimens. It is one of the earliest formed minerals at the locahty, 

 since individuals of spodiophyllite sometimes occur imbedded in 

 aegirine crystals. Amongst the other minerals closely associated 

 with the spodiophyllite the following ought to be mentioned: 

 zircon of type II, ancylite, rhodochrosite, and albite, all of 

 which are of later formation. 



