69 



SULVANITE : A NEW MINERAL. 

 By G» A. Goyder. 



[Read June 5, 1900.] 



Some specimens were sent to the Assay Department of the 

 Adelaide School of Mines and Industries for assay for copper by 

 Mr. E. Meylan, of Port Pirie, who stated that they were obtained 

 from a new mine near the Burra. 



During the analysis for copper I found that they contained 

 vanadium, and therefore wrote for further samples, which Mr. 

 Meylan promptly sent. 



On examination these proved to consist of malachite, azurite, 

 vanadium ochre, quartz, calcite, gypsum, and a metallic mineral, 

 consisting principally of copper, sulphur, and vanadium. 



A small piece of this mineral, as free as possible from associated 

 minerals, was powdered and digested with acetic acid (which 

 removed some malachite and calcite), washed, dried, and 

 analysed. There was not sufficient for an accurate analysis in 

 detail, but the following figures were obtained : — 



Per cent. Per cent. Per cent. 



Copper, 58-82 Vanadium, 11-88 Sulphur, 26- 44 



the balance being silica, lime, and a trace of iron. 



The ratio of copper to vanadium was confirmed by a duplicate 

 analysis of a smaller sample by a different method of analysis. 



The mineral was found to contain no sulphur in the form of 

 sulphate, and on heating in a closed tube it gave off no sulphur, 

 from which it would appear that the copper must be in the form 

 of Cu 2 S, with the vanadium as "V S S 3 . The ratio of Cu 2 S to 

 V 2 S 3 in the sample analysed is 3^ to 1, but an analysis of some 

 other specimens not so pure proved them to contain an oxidized 

 vanadium mineral with a smaller relative proportion of copper, 

 so that the composition of the mineral is most probably 4Cu 2 S, 

 V 2 S 3 , which constitutes it a basic sulpho-vanadite of copper.* 



The samples sent me were all in a more or less oxidized form, 

 and as the mineral is not distinctly crystalline, and is penetrated 

 by oxidised products almost throughout, its physical properties 

 cannot be accurately ascertained, 



* Subsequent analyses show that the mineral is a sulpho- vanadate of 

 copper, 3Cu 2 S, V 2 S 5 . 



