From the beginning of the 16th century until the end of the 18th century, Leogang was famous throughout Europe for its abundance of cobalt and nickel ores.
From the mid-16th century, cobalt ores were of particular importance. In blue colouring works’, safflorite was first produced by heating cobalt ore. This served as the raw material for the production of smalt, a powdery blue glass pigment. Since both safflorite and smalt are fireproof, they were used for colouring glass, porcelain, ceramics and oil paints.
Coloured Venetian glass was seen as a special luxury in the German-speaking countries of Europe from the mid-15th century. German merchants such as the Welser and Fugger families had already founded the Fondaco dei Tedeschi (‘the Germans’ warehouse’) in Venice in 1225. Situated on the Canale Grande right next to the famous Rialto Bridge, the building became the trading centre for luxury export goods from Venice to the German-speaking countries.
As the use of safflorite and smalt for colouring glass increased, cobalt from Salzburg became an indispensable raw material for the production of luxury Venetian glass from the mid-16th century.
Its extraction and use in glassware is mentioned in Georg Agricola’s De re metallica Libri XII from 1556, a masterpiece of mining literature which can also be admired at the Leogang Mining and Gothic Museum.
There was an unprecedented increase in the use of blue in painting too. From as early as the 12th century, what was at first a dark and lacklustre colour was redefined as the symbol of Heaven and the virginity of the Blessed Mother. Glassmakers and illuminators strove to reconcile this new kind of blue with church architects’ altered perception of light adopted from theologians. The radiance of cobalt blue oil paint opened up a completely new set of possibilities in the visual arts.
Today, smalt, or cobalt blue glass powder, is mostly used for restoring old masterpieces.