The Minting of Platinum Roubles - PART II: The Platinum Roubles of Heraeus

Heraeus has in its possession four platinum rouble coins and one commemorative platinum medallion minted between 1826 and 1844. In order to determine their composition and to learn a little more about the methods used in their manufacture, they have been subjected to various techniques of non-destructive examination. These have included a developmental SQUID microscope specifically used to look at magnetic effects due to the iron content.