125 



ON THE FORMATION OF MOSS GOLD AND SILVER. 



By Archibald Liversidge, 



Professor of Geology and Mineralogy in tlie University of Sydney. 



[Head before the Royal Society of N.S. W., 6 September, 1876.] 



The origin and mode of occurrence of certain of the metals 

 which are found in the free or native state, both in mineral 

 veins and disseminated through various rocks, has for some time 

 been a question of much interest to me ; my attention, however, 

 has hitherto been directed more particularly to the circumstances 

 connected with the occurrence of native gold and of the minerals 

 with which it is usually found associated ; and it was while per- 

 forming an experiment to ascertain, if possible, whether the gold 

 which Avas known to be present in a certain specimen of mis- 

 pickel, existed in the crystallized state, or was merely disseminated 

 through the mineral in amorphous particles, that I first obtained 

 the '"peculiar form of gold which I now have the pleasure to 

 exhibit to the Society. 



I have called this remarkable, and to myself hitherto unknown 

 artificial form of the metal " moss gold," because in many respects 

 it resembles the well-known "moss copper," hence it is convenient 

 to use the above term for it ; although it should be stated that 

 none of the specimens of gold presented anything like so velvety 

 an appearance as that commonly exhibited by moss copper. 



One of the two specimens before me was a rich piece of mis- 

 pickel from the Uncle Tom Mine, near Orange, I believe, and 

 the other a somewhat richer specimen from Paxton's, or the 

 Rampant Lion Mine, Hawkins' Hill, obtained from a depth of 

 200 feet. Both contained some visible gold, the first only a few 

 small specks, but the second was fairly rich in free gold, although 

 the amount was not to be compared to that which it now shows. 

 Mispickel, I may remark, is a compound of arsenic, sulphur, 

 and iron, combined in the following proportions, — 



Iron = 34'4! 



Sulphur = 19-6 (orPeAs^PeSo) 



Arsenic = 46*0 



100-00 



The first specimen was roasted in a mufile in order to expel 

 the sulphur and arsenic, and my intention then was to dissolve 



H 



