Formation of Gold Nuggets. 59 



to the silica in the reef, we will find no difficulty in admit- 

 ting that silicate of gold may exist in solution. 



In several instances an amathistine colour has been 

 observed, both in the quartz reefs and in the "washdirt" 

 of the drifts. Mr. Aplin tells me that he observed it in a 

 lead of washdirt near Beechworth. When pieces of the clay 

 so coloured were first broken out no gold was to be seen ; 

 but after exposure to the light and air for a short time the 

 colour disappeared, and it was seen to be full of very finely 

 divided gold. Mr. Ulrich also tells me that this colour and 

 phenomena were observed by a Mr. Clement, a successful 

 quartz miner, of Maldon, who described having found dark 

 blue clayey bands in the centre of a quartz reef, some ten 

 feet thick, at a depth of about seventy feet from the surface. 

 The colour in this case, as in that reported by Mr. Aplin, 

 disappeared when exposed to air and light, and gold became 

 visible. It is to be regretted that no chemical examination 

 was made, as there was undoubtedly a compound of gold 

 present. 



Be this as it may, there can be no doubt that nearly all 

 the native sulphides contain gold, especially those which 

 also contain silver. I have found it with this metal 

 in every sample of iron, copper, and arsenical pyrites 

 galena, sulphide of antimony and zinc blended, which I 

 have examined from the rocks of this colony ; and Dr. Percy 

 proved its existence in every sample of galena he examined, 

 even though they contained little or no silver. BischofT, in 

 reviewing facts like these, says that it has been repeatedly 

 proved that in the decomposition of ore lodes, the silver 

 takes part in the oxidation processes, and is removed in 

 soluble combinations. m If such ores are auriferous, and after 

 such a decomposition the lodes undergo mechanical destruc- 

 tion, the gold will, as it is in a very minute state, be carried 

 off with the results of the decomposition. The argentiferous 

 character of the native gold, and the auriferous character of 

 native silver, show that though one metal passed into a soluble 

 form and the other remained metallic ; the separation was not 

 complete. 



In this very minute state gold may possess properties 

 differing from those which it has when in mass. Iron, for 

 instance, when reduced by hydrogen from the oxide, has 

 such a great affinity for oxygen, that, if dropped through the 

 air at the ordinary temperature it takes fire, whilst ordinary 

 iron filings, under similar circumstances, are not affected. 



