51 



the analysis, the result of which is given below, was obtained 

 from the "Wallaroo Mine. The crystals were about i inch long. 

 The analysis of this specimen yielded the following results 

 (i), and for the sake of comparison I subjoin (ii) the analysis 

 of a specimen from Chili as quoted by Dana : — 



Copper 

 Chlorine ... 

 Cupric oxide 



Water 



Insoluble silicious residue 



1000 99-85 



* The water in this instance was obtained by difference. 



PiSTOMESITE. 



This mineral occurs in large quantities at the Balhannah 

 Mine, the waste tip being for the most part formed of it. 

 "When first obtained this mineral is of a yellowish-gre}' colour, 

 but on exposure it assumes a bronze-coloured coating. 



A preliminary examination showed that the mineral consisted 

 of magnesic and ferrous and manganous carbonates, and at first 

 I was inclined to think that it was Breunnerite, a ferriferous 

 variety of Magnesite. A complete quantitative analysis showed, 

 however, that the mineral had the composition of Pistomesite, 

 with which it also agrees in its physical properties. The 

 specimen for examination was selected from the centre of a 

 large mass, and was free from the incrustation referred to 

 above. The result of the analysis was as follows (i), JN'o. ii 

 being the analysis of a specimen from Thurnburg quoted by 

 Dana : — 



99-98 99-26 



The hardness of the Balhannah specimen was 3-5, and the 

 specific gravity 3-5, that of the Thurnburg specimen is given 

 at 3-4. 



SiDEEITE. 



The specimen examined was obtained from the Ivarkulto 

 Mine ; it was in the form of a largely crystalline mass, of a 

 brownish-grey colour. Hardness 3-5, and specific gravity 3-9. 



