In a fascinating discovery, experts at the Bavarian Environment Agency (LfU Bayern) in Germany stumbled upon fragments of one of the rarest minerals on Earth, Humboldtine, during a survey of a historic mineral collection. Humboldtine is a unique iron-carbon-oxygen mineral that contains water and has only been found at 30 locations worldwide. It is primarily observed as a yellow, shapeless mass, and only occasionally forms tiny crystals. This mineral is formed through the reaction of carbon compounds with iron-rich water and oxygen.
The story of Humboldtine dates back to its initial discovery in 1821 by German mineralogist August Breithaupt. The mineral was found in a weathered brown coal deposit near Korozluky in the Czech Republic and was named after the renowned German naturalist Alexander von Humboldt by Peruvian geologist Mariano Eduardo de Rivero y Ustariz. Since then, the mineral has remained a subject of intrigue and study within the scientific community.
The latest chapter in the Humboldtine saga unfolded in 2023 during the digitization of LfU's archive. A letter written and sent by a coal mine owner back in 1949 was uncovered, mentioning the presence of Humboldtine in the coal seams near the town of Schwandorf in the Upper Palatinate. The agency's curiosity was piqued, leading them to request samples to confirm the discovery. Unfortunately, no further documentation regarding this finding exists.
Nevertheless, driven by the note's implications, Roland Eichhorn, the head of LfU's geological department, embarked on a quest to explore their vast historic mineral collection. With over 130,000 rock and mineral samples stored in the agency's basement, the chances of finding any previously sent-in samples seemed promising. Following an exhaustive search, Eichhorn and his team managed to locate fragments of a yellow mineral labeled 'Oxale' in a drawer of the systematic mineral collection. The samples were accompanied by a note confirming their origin from the specified locality mentioned in the 1949 letter.
Modern chemical analysis of these fragments confirmed that the discovery made 75 years ago was indeed Humboldtine. While the six fragments found may not be substantial in size, with the largest resembling a nut, they have effectively doubled the known amount of Humboldtine specimens in existence.
Unfortunately, there is some bad news for mineral collectors hoping to get their hands on more Humboldtine. The Mathiaszeche, the former open-pit brown coal mine mentioned in the 1949 letter, was shut down in the early 1980s and subsequently flooded, making further extraction from this locality impossible.
This serendipitous find not only sheds light on the existence of Humboldtine in an unforeseen location but also highlights the importance of preserving historical mineral collections. The discovery reiterates the valuable insights and potential surprises that lie hidden within these archives, awaiting further exploration and investigation.
As we continue to learn more about Earth's mineralogical treasures, the story of Humboldtine reminds us of the vastness and intricacy of our planet's geology, continuously captivating scientists and enthusiasts alike.
