The inscription round the rim of this copper cup explains its history and original appeal. It alludes to the method of obtaining copper in the Herrengrund area of present-day Hungary.
Because of the peculiar geological properties of the region, the local water had a high concentration of copper sulphate. Iron scraps were placed in hollows where the water collected and reacted with the copper sulphate to precipitate copper out of solution. The copper either settled as a sludge or formed a crust over the surface of the iron. This gave rise to the legend that the water had mysterious, if not magical, properties. Inscriptions on puzzle cups like this one read ‘Iron I was, copper I am…’ or ‘First Herrengrund’.
Such cups were often adorned with small maquettes (models) representing miners at work. They were showpieces, and the persistence of the legend inscribed on the rims reflects the public ignorance of metallurgy. These puzzle cups were popular throughout Europe during the period 1500-1700. After this, popular knowledge of chemistry increased and this type of object inevitably became less attractive.