56 



acid in solution has gradually converted it into lead carbonate, 

 the action taking place most actively along the cubical cleavage 

 cracks off the original galena. At a later date carbonate of 

 copper was deposited superficially. 



Anglesite, sulphate of lead : a colourless mineral with high 

 lustre, in many respects resembling cerussite in appearance. 

 The specimens exhibited come almost entirely from Broken Hill. 

 Anglesite is often founded seated on cerussite. Case 46 

 contains a very fine specimen from Block 14. 



PyromorpTiite, phosphate and chloride of lead : frequently 

 yellow ; the crystals form characteristic six-sided prisms with 

 flat terminations Unlike galena and cerussite, this ore of lead 

 seldom carries silver. The mineral occurs in a number of 

 localities, the best crystals coming from the Mount Stewart 

 Mine, Leadville, from Broken Hill, and from the Wallah AVallah 

 Silver Mine, Bye Park. 



1545, Mount Stewart : greenish-yellow crystals showing the 

 characteristic form ; two exceptionally fine specimens from here 

 will be found in case 46 (Plate III). 



1220, Block 14, Broken Hill : yellow crystals. 1040, Block 

 14, Broken Plill, shows hollow crystals. 806, Cobar : on slate. 

 8737, Goulburn : on ironstone. 



5711, typical of a massive yellow variety not uncommon in the 

 ^raidvvood district ; it has the following composition : — 



Lead oxide ... ... ... 6940 



Lead 6-57 



Phosphoric anhydride ... ... 15'22 



Chlorine 2-26 



No gold or silver. 



A less common variety (6521) is found at the Junction Mine, 

 Broken Hill. It occurs in fragile clusters of crystals of an ashen 

 colour. Case 46 contains two very fine specimens of this 

 variety, 



