102 



ment, consequently, takes place within a range of temperature 

 of 10°— 20°. 



For the analysis material was taken from the specimens 

 with imperfect crystals. The specific gravity was found , by 

 weighing in benzole, to be 2,781. The mineral yields all its 

 water at a low red heat. At this temperature the powder does 

 not fuse at all, but it becomes insoluble in acids in which it 

 is easily soluble before ignition. In the analysis one gets a 

 considerable part of the zirconia together with the silicic acid, 

 from which it is liberated by hydrofluoric acid and sulphuric 

 acid. The zirconia in the solution is precipitated together with 

 the ferric oxide by ammonia, iron and zirconia are separated 

 by sulphide of ammonium in the presence of tartaric acid. The 

 analysis gave the following result: 



Calculated. 



SiO^ 44,70 45,05 



ZrO^ 30,85 30,43 



FeO 0,71 — 



Na^ 14,09 15,51 



H.,0 9,07 9,01 



99,38 100,00 



The annexed calculated percentage composition is obtained 

 from the formula 



Na,_SiO., -H.ZriSiOj.,. 



Catapleiite crystals of type 111 have been found onNarsarsuk 

 only at the locality No. 3, the same place where those of type I 

 were met with. Only loose specimens bearing the mineral were 

 observed, and as no trace of the catapleiite of type I occurred 

 on them , the mutual relation of the two types with regard to 

 their order of formation etc. cannot be decided. The most 

 important minerals that accompany the catapleiite on the spe- 

 cimens , are feldspar, fine-grained; aegirine in small, 



