Tankard

The excellent engraving work shows putti personifying the four seasons. Pure gold, in the form of nanometer- sized particles, is responsible for the luminous ruby-red colour of this Glass, also known as gold ruby Glass. However, it is extremely difficult to produce Glass Objects such as this. The alchemist Johann Rudolph Glauber (1604 – 1670) discovered one method around the mid-17th century. Glauber was not primarily interested in the beauty of the colour; instead, he claimed to have found the “essence” of gold, and with it the key to “transmutation,” the transformation of metals which alchemists had been attempting for centuries. A few decades later, the Glassmaker and alchemist Johann Kunckel (1637?–1703) used Glauber’s technique in Potsdam to make the first large gold-ruby Glass vessels. In recognition of this success, Prince-Elector Friedrich Wilhelm I of Brandenburg (ruled 1640–1688) gave Kunckel the Pfaueninsel (Peacock Island) near Berlin. (Dedo von Kerssenbrock-Krosigk)