Sirupate:
  
  I think it helps, Simon, if we can all take a look at the article you mentioned and know what it is that we are discussing. Attached is a PDF copy of what I believe to be that article. Thank you for bringing this to our attention. 
I am reminded of a recent discussion on copper alloys with regard to the use of 
samrit ("auspicious alloy") in a recent SE Asian thread (
http://www.vikingsword.com/vb/showth...ghlight=samrit).
  
  Ian.
  
  Attached reference: 
O'DUBHGHAILL, C. & JONES, A.H.  Japanese irogane alloys and patination—a study of production and application.  Available from Sheffield Hallam University Research Archive (SHURA) at:  
http://shura.shu.ac.uk/971/
  
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