Experts have discovered hazelnut-sized chunks of the extremely rare mineral Humboldtin in a rock collection in northern Bavaria. So far, tiny crystals have only been found in a few places worldwide, explained the head of the geological service at the State Office for the Environment, Roland Eichhorn, in Hof. Together these would roughly form a snowball that would fit in one hand. “And we have now found a second snowball.”

The Humboldtin is named after the natural scientist Alexander von Humboldt. “It’s the cyborg of minerals,” said Eichhorn. It consists of carbon and water like all life on earth – but at the same time it also contains iron.

Searched and found – in 130,000 exhibits

According to him, it was not known for a long time that this rarity was in the rock collection in Upper Franconia. Employees are currently digitizing the collection’s archive. They came across a 75-year-old letter that tells about the mineral. However, it was not listed in the catalog. So the team searched the entire collection of 130,000 exhibits. She finally discovered the yellow chunks and the label in a small box.

Analyzes in the laboratory showed that it was actually Humboldtin. According to Eichhorn, this comes from a lignite mining area near Schwandorf in the Upper Palatinate – and will probably continue to puzzle researchers. Brown coal mining was abandoned and the area was filled with water in the 1980s. “There is no longer any way to examine the site to get clues as to how the Humboldtin came about,” said Eichhorn.

But mineral fans will have an opportunity to admire it: it will be on display at the Geological Survey’s stand at Europe’s largest mineral trade fair in October 2024.