490 A. J. Moses — Miner aloc/iaal Notes. 



Before the blowpipe the mineral fuses readily coloring the 

 flame red and forming a white enamel. On grinding it is 

 damp and adhesive. Dissolves partially in water "to an alkaline 

 solution and is rapidly and completely decomposed by hydro- 

 chloric or even acetic acid. 



It differs from the ettringite of Prof. Lehmann in that the 

 latter occurs in needle-like hexagonal crystals, has a recorded 

 specific gravity of 1*75 and is said to be infusible. 



From the tendency of the portions of the silicate nearest the 

 sulphate to crumble the material for analysis had to be picked 

 almost fiber by fiber. Upon the purest sample thus obtained 

 a complete analysis yielded : 



No. I. 

 On -2235 grms. 



CaO _. 25-615 



Al o 3 : -__ 10-157 



SO; 17-675 



H 2 (at 115°) 33-109 



Loss (at red heat) 10-872 



SiO„ 1-901 



99-329 



The Si0 2 is present as a silicate more or less impregnated 

 with metallic ores but which two analyses show to contain 

 proportionately SiO„ 100 pts., CaO 27-89 pts., A1 2 3 47-02 pts., 

 H 2 (at 115°) 9-70 pts., H 2 (at red heat) 25-97 pts. Deduct- 

 ing in this proportion and recalculating to 100 we have : 



No. I (recalculated). 



CaO 26-31 



A1„0 3 .. 9-72 



SO s 18-54 



H 2 0(115°) 34-53 



H 2 (red heat) 10-88 



To prove that there had been no volatilization of S0 3 or 

 reduction to sulphide during ignition -2088 gms. of the min- 

 eral was dissolved in acid without ignition and the S0 3 and Si0 2 

 determined. 



S0 3 15-066 



Si0 2 ... 9-909 



Recalculated as in previous analysis this corresponded to 

 S0 3 19-03. 



An attempt was made to obtain another complete analysis 

 on a sample of material not quite so pure as the first but in 

 the ignition there was a loss of S0 3 due partly to reduction to 



