

198 



From this is calculated: 



à:b:c = 1-1496: 1 : 10343; 



ß = 85° 32' = (001) : (lOO). 



For the pectolite is : 



à:t:c = 1-1140: 1 : 0-9864; 



ß = 84° 40' = (001) : (lOO).M 



The optic axial plane forms a right angle with {OIO). 

 The mineral is optically positive. Of the axes of elasticity is 



J. I 



с = b. b lies in the acute angle between the axes à and c. 

 cb = 13° 8'. 



The angle between the optic axes 

 is for sodiumlight: 2Ey = 82° 40'. 

 The double refraction for sodiumlight, 

 measured on {lOO} is 0.02711. 



The specific gravity is stated in 

 pycnometer to 3-089. The hardness 

 is 6-5V2. 



Chemical composition. The ana- 

 lysis was made by cand. polyt. Chr. 

 Christensen, who states the fol- 

 lowing regarding it: 



«The mineral was decomposed 

 with sodium carbonate. The silica 

 was evaporated with hydrofluoric acid. In the filtrate from the 

 silica titanium was precipitated with sodium hyposulphite.» 

 «Another portion was treated in a platinum-basin with 

 hydrofluoric and sulphuric acid and afterwards oxydized with 

 bromine. The excess of bromine was driven off by boiling. 

 Fe, Ti were precipitated with sodium acetate. Mn^ Ce were 

 then precipitated with ammonium sulphide; the precipitate 



Fig. 4. Schizolite, 

 optic scheme. 



') Dana, System of Mineralogy 1893, Page 373. 



