This is a late 17th century tourist souvenir. It comes from the Herrengrund copper mines in modern day Slovakia, a place where the water was believed to perform miracles almost akin to alchemy. High in copper sulphate, the water was diverted into hollows, where scraps of iron had been placed. The copper sulphate reacted with the iron, depositing a coating of copper on the scraps and giving them the appearance of copper rather than iron. This gave rise to the legend that the water had mysterious, magical properties. The inscription on the outside of the rim translates as: ‘I come from iron but the power of the water has turned me into copper in a mine in Herrengrund’.
In the centre of the cup is the small figure of a miner at work, hammering away at crystals of iron pyrites. The inside of the cup is plain and functional, so it is possible that this is a working souvenir. Its purchaser may have been encouraged to take the cup, scoop up the local water and then watch the copper deposits appear on the iron pyrites.
- V&A Search the Collections catalogue entry: http://collections.vam.ac.uk/item/O67241/cup-unknown