Cobalt is a critical raw material today, due to its essential value in battery technology. We need cobalt for the green transition, as addressed in the GeoERA projects FRAME and MINDeSEA. However, cobalt was also a critical raw material long before our modern needs. For hundreds of years, cobalt was the most attractive resource for blue pigment – “cobalt blue” providing the illusion of sky and sea to glass and optical filters, for fine porcelain and potteries, and for paint.

A historic mine in Norway, ‘Cobalt Mines at Blaafarvevækret’, tells the story. From 1772 to 1893, this mine was one of the most important in the world, and in the heydays, 2000 people were employed. Now, it is a museum worth visiting, offering a guided tour in a part of the mine called ‘Clara Adit’. The Glück Auf Strasse suspension bridge in Clara Adit saluts German miners. Cobalt was also mined in Sweden, Hungary and Germany. New explorations for cobalt is taking place in the same geological formations, but for different purposes. Cobalt is also found in environments completely alien to humans, namely in ferromanganese crusts and polymetallic nodules on the deep sea floor up to 6000 m water depth. While the use of raw material changes, our society always value some of them more critical than others.