31 



the more important mining divisions. Specimens from any 

 neighbourhood can be quicivly found by referring first to the 

 geographical district and then to the mining division in which 

 it is situated. 



Gopeland, Stewarf s BrooJc, Walc]ia,and neighhouring Divisions. Case 50. 



5835, Moor Creek, Tamworth : interesting in containing free District, 

 gold associated with telluride of bismnth — the leaden-looking 

 mineral. 



9543, near Moonbi : represents a most unusual mode of 

 occurrence for gold. The ore is a deeply copper-stained garnet 

 rock, assaying 4| dwt. gold to the ton. 



Upright cases 125 and 128, at the lower end of the room, 

 contain block specimens of gold quartz from the Hanging Sock, 

 Nundle. 



mUgrove, Dalmorton, Bingcira, Coramha, Woodhurn, and CaSG 51. 

 neighbouring localities. — 6973 : granite, the country rock of the 

 TJralla Gold-field. 



Prom the Hillgrove Grold-field will be found many specimens 

 of great interest. The country rock here is an ancient slate 

 (and also to some extent the adjacent granite), which has been 

 shattered along certain directions by movements in the Earth's 

 Crust. The resulting fragments have been cemented together 

 by quartz which has been accompanied by antimonite and gold 

 (sometimes free). Notice particularly 6615, 6612, 2484, 2567, 

 and a yery fine block specimen in case 136, near the door. 

 Sometimes the gold is visible (6615 and other specimens here, 

 also 2131 in case 125 at lower end of room). 2525 shows a 

 slickensided surface, proving that movements have taken place 

 between neighbouring masses of rock. 



In case 125 will be found a mass of crystallised pyrites, assay- 

 ing 4 oz. of gold to the ton, from Glen Elgin. 



61 and other specimens from Deep Creek, JSFambucca, bring 

 before us the combination of gold with" arsenical pyrites 

 {mispicJceV) . These ores are more diflScult to treat.* 



* Pure arsenical pyrites now has a commercial value of its own on account of its arsenic 

 contents, — see page 79. 



