Mr Solly, Liveingite, a new mineral from the Binnenthal. 239 



Liveingite, a new mineral from the Binnenthal. By R. H. 

 Solly, M.A., Downing College, with analysis by H. Jackson, M.A., 

 Downing College. 



[Abstract, read 6 May 1901.] 



This new mineral, to which I have given the name "Liveingite" 

 in honour of the Professor of Chemistry, G. D. Liveing, F.R.S., is 

 a new member of the group of sulpharsenites of lead which com- 

 prise Sartorite PbS + As 2 S 3 , Rathite SPbS + 2As 2 S 3 , Dufrenoysite 

 2PbS + As 2 S 3 and Jordanite 4PbS + As 2 S 3 . 



It crystallizes in the oblique system with a pseudo-rhombic 

 habit, /3=89°45i'. 



The crystals consist of a twin aggregation, twinned about 



( 10 °)- 



The twinning is beautifully shown by the iridescent tarnish 



they exhibit ; one crystal has a green shade of colour, the other a 



red. 



This difference in colour of two similar twinned crystals is well 

 shown in Jordanite. 



Through the kindness of Professor Liveing I have lately been 

 able to make a few experiments on the artificial tarnishing of 

 twinned crystals. The experiments made on Bournonite and 

 Redruthite confirm the arrangement of tarnish observed in Live- 

 ingite and Jordanite. 



The crystal habit is partially like Rathite and Sartorite. 



The development of the dome zone resembles Rathite, while 

 in the prism it resembles Sartorite. The pyramid zone has planes 

 not found on either Rathite or Sartorite. 



The prism zone exhibits oblique symmetry. I had only two 

 crystals and the greater portion has been used by Mr Jackson in 

 his analysis. 



I am hoping to obtain this summer more material so as to be 

 able to fully describe the crystallographic characters of this new 

 mineral. 



R. H. S. 



