544 



GEOLOGY AND MINING INDUSTRY OF LEADYILLE. 



No. 1, from the Adelaide mine, is an extremely pure white sand, made 

 up of small crystals of cerussite, and in the mass looking not unlike a 

 coarse white sandstone. These white sands are, as a rule, less rich in silver 

 than the discolored and relatively impure ones, but this has exceptionally 

 little silver. It does not occur in the Blue Limestone or in the immediate 

 vicinity of it, but between the White and Gray Porphyries. 



No. 2, from the Little Chief mine, is a rich sand-carbonate, discolored 

 and appearing to contain more impurities than it really does. 



No. 3, from the Waterloo mine, is also a discolored carbonate, less rich 

 than the former, in which onl}- the constituents of cerussite and pyromor- 

 phite were determined qualitatively. 



No. 4 is the analysis of a mixture of ores made by Mr. Th. Fluegger, 

 chemist of the Harrison Reduction Works. It was made for the purpose of 

 showing the average proportions of the most common elements in the ore, 

 and it may be assumed that neither did the laboratory facilities at his 

 command admit of, nor his purpose demand, an equal standard of accuracy 

 with the others in regard to the rarer elements and their combinations. 



Carbonate ores. 

 \. Adelaide. 2. Little Chief. 3. Waterloo. , 4. Average ore. 



PbO.... 

 AI2O3... 

 FesOa -. 

 FeO .... 

 MnO ... 



MnOa... 

 CoO .... 

 ZnO .... 

 CaO .... 

 MgO .-. 

 SiOi .... 

 SbiOs... 

 A32O5... 

 PiOi— - 



SO3 



CO2 



CI 



HjO .... 



Ag 



Att 



80. 352 

 0.444 

 0.407 

 0.299 

 0.137 



0.303 

 0.068 

 O.OJl 



Trace 

 1.532 

 Trace 

 14. 700 

 0.255 

 0.385 

 0.009 

 Trace 

 99. 012 



75. 408 

 1.415 

 1.940 



1.386 

 Trace 

 0.095 

 0.335 

 0.056 

 1.972 

 0.121 

 Trace 

 Trace 

 0.486 

 14. 251 

 0.288 

 1.140 

 0.777 

 Trace 

 99. 744 



10. 180 

 0.840 



24.86 

 0.89 

 4.03 



! NaaO S 



Trace 



2.36 



3.04 



22. 59 



Sb= 0.02 



A3.= 0.01 



S= 0.90 

 5.58 



0.31 

 Trace 



