6 Report on the Copper Ores of the Deoghur Mines. [No. 8. 



From H. Piddington, Curator Museum of Economic Geology, 

 To W. Seton Karr, Esq., Under Secretary to the Government of 



Bengal. 



Sir, — In continuation of my Secret Service letter of 3rd July, 

 I have now the honor to submit for the information of Government a 

 detailed report on such of the ores of the Deoghur mines as have 

 reached me. 



His Honor will be satisfied to see that from two of the classes of 

 ores, of which only I could obtain a sufficient quantity for the experi- 

 ment, the produce in silver has been a fair and a good average ; though 

 these are still but surface specimens, and that moreover (and upon this 

 depends their value) the Spanish American process of amalgamation 

 can be successfully practised at what may be supposed theoretically the 

 very worst period of the year in India. 



We have now to hope that the deposits, if wrought, will be found 

 abundant. 



(Signed) H. Piddington, 



Curator Museum Economical Geology. 



Calcutta, 3\st December, 1850. 



Report. 



Part I. — The Rocks. 



In forwarding these specimens Captain Sherwill has sent also speci- 

 mens of the rocks in which the vein lies, and to avoid confusion I 

 briefly describe these separately from the ores. 



No. 1 . A garnetiferous gneiss with horizontal veins of quartz pass- 

 ing through it, forms the general bed of the country at Deoghur.* 



No. 2. Gneiss with thin veins of quartz, no garnets. 



No. 3. Decomposing pegmatite, forming the gangue in which the 

 metallic veins are found ; Sa. 3b. 3c. coarse granular pegmatite found 

 on the surface of the country and contains the ores : It is all more or 

 less decomposing. 



No. 4. Altered quartz rock, in some places nearly a jasper, and 

 stained green by copper infiltrations. 



* These passages in Italics are Captain Sherwill's Notes. 



