WWJ-Detroit shares that a bright blue mineral has been discovered at a mine on the Keweenaw Peninsula that so far has people perplexed:
The mysterious mineral was found on rock walls in the historic U.P. Adventure copper mine in Greenland Township, south of Lake Superior.
On Sunday, officials from the mine have posted pictures on Facebook of the mystery substance found on rock walls, but the bright blue material has not been positively identified.
Officials said they believe it to be a secondary mineral caused by a reaction with air and water. The mine operated from 1850 until 1920 and 11 million lbs. of native copper has been extracted.
Definitely visit the Adventure Mine website for information on their tours & the history of the mine. In the Facebook post referenced, Adventure Mine said “This bright blue mineral has not been positively identified as of this post but it is a secondary mineral that is caused by a reaction with air and water. It was found on the 3rd level in a small stope.” A stope is an excavation in a mine working or quarry in the form of a step or notch & the comment thread has some very interesting ideas as to what the mineral could be.
My own personal pet theory based solely on how cool it would be is that this reaction is due to the same mineral that creates the unique iron ore slag known as Leland Blue.
PS: After some discussion with Adventure Mine operators, I realize that I took my kids on a tour there 20 years ago. Super cool & a highlight of our visit to the awesome Keweenaw Peninsula – definitely put a trip to the copper-iest of Copper Country on your Michigan bucket list!