By Shawn M. Carlson*
Cubanite crystal, a copper-iron sulfide mineral, from Marquette County, Michigan. (Photo by D. John A. Jaszczak and courtesy Shawn M. Carlson)
What different types of minerals can be found in Michigan? Which of them are ore minerals, open to potential development by mining companies? Does Michigan have any toxic or radioactive minerals, and where might they be located? And where are the best locations to seek out gemstones and other collectibles such as agates, datolite, and Michigan greenstone? These were the questions that University of Michigan mineralogist E. Wm. Heinrich attempted to answer in his classic 1976 monograph, The Mineralogy of Michigan. Published as "bulletin 6" by the Department of Natural Resources, Geology Survey Division, this book contained a brief discussion of the various types of mineral deposits known in Michigan, followed by an alphabetical listing of mineral species, along with their locations. It was the first attempt in our state’s history to assemble a complete listing of all minerals known to exist in Michigan.
In 2004, being mindful that nearly three decades had passed since Heinrich’s compilation, a second edition of the Mineralogy of Michigan was published, this time by Dr. George W. Robinson, mineralogy professor at Michigan Technological University and curator of the A. E. Seaman Mineral Museum. This version significantly expanded upon the number of mineral species known to occur in Michigan; and it included a discussion of the discovery of diamond-bearing kimberlite pipes and the intense exploration pressure in the 1980s and 1990s to develop a gem diamond mine in the Upper Peninsula -- an intriguing and somewhat clandestine chapter in the history of Michigan mineral exploration that had not yet unfolded at the time of Heinrich’s 1976 monograph.
Gem diamond crystal from Michigan. (Photo by Torrie Chartier and courtesy Shawn M. Carlson)
Due in part to the current high level of public interest in Michigan mineral exploration and new mining ventures, a third version of the Mineralogy of Michigan has just been released, again written by Dr. George W. Robinson, in collaboration with industry mineralogist Shawn M. Carlson. This work is an attempt to list all new and important mineral discoveries made in Michigan since the 2004 second edition, including finds made by mining and mineral exploration companies, scientific researchers, students, and hobby mineral collectors. Of particular note, this version contains updated information on
mercury and selenium minerals, uranium species, and minerals formed by acid mine drainage -- as well new locations for amethyst, topaz, tourmaline, and many other species of interest to the collector and lapidary community. The document is available on the Michigan Tech website at museum.mtu.edu/news/museum_news.htm.
Echoing the spirit of Heinrich’s 1976 monograph, it is hoped that this latest version will be of interest and use to professional earth scientists and beachcombers alike.
* Editor's Note: Guest author Shawn M. Carlson, of Crystal Falls, Mich., is an industry mineralogist and the co-author, with Dr. George W. Robinson, of the 2013 Mineralogy of Michigan Update.