Mindat Logo

Caledonia Mine, Mass City, Ontonagon Co., Michigan, USA
This page is currently not sponsored. Click here to sponsor this page.

An underground copper mine consisting of two shafts and four adits located approx. 40 miles SW of Houghton, MI. The Caledonia Mining Co. was organized in 1863 after purchasing the Nebraska and Kansas Mining Co. properties. Operations continued until 1871, when Caledonia and the Flinsteel Copper Co. merged together. In 1872, the mine closed having produced approx. 903,000 lbs. of refined copper. From 1873 to 1881, the mine was tributed and another 330,000 lbs. of copper was produced, including one mass weighing 40 tons. The mine was dormant until 1937, when Calumet & Hecla reopened the #4 adit for exploration, but stopped the project due to World War 2. In 1950, C&H returned to continue exploration, drifting, and stoping. Between 1951 and 1958, C&H removed approx. 5.5 million lbs. of refined copper from the #4 adit. In 1985, Red Metal Explorations acquired the Caledonia Mine and conducted exploration of the property until 2013, when Evergreen Explorations purchased the property. The mine is the centerpiece for a week long series of mineral collecting field trips in August put on by local organizations. The mine is exceptional for copper, silver, and datolite, as well as a range of microminerals.

Mineral List

var: Pennine

'K Feldspar
var: Adularia'


19 entries listed. 16 valid minerals.

The above list contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.


Rocks & Min.: 58:112; 63:494; 65:240-243

Butler, B.S., and Burbank, W.S., 1929, The Copper Deposits of Michigan. U.S. Geological Survey. Professional Paper 144. 238 pp.

The Copper Country Rock & Mineral Club, 2001, Red Gold and Tarnished Silver, 2nd Ed., 44 pp.

Mineral and/or Locality  
Search Google  
Copyright © Jolyon Ralph and Ida Chau 1993-2014. Site Map. Locality, mineral & photograph data are the copyright of the individuals who submitted them. Site hosted & developed by Jolyon Ralph. Mindat.org is an online information resource dedicated to providing free mineralogical information to all. Mindat relies on the contributions of thousands of members and supporters. Mindat does not offer minerals for sale. If you would like to add information to improve the quality of our database, then click here to register.
Current server date and time: December 20, 2014 15:07:36 Page generated: December 19, 2014 03:31:36
Mineral and Locality Search
and/or Locality:
Fade toolbar when not in focusFix toolbar to bottom of page
Hide Social Media Links
Slideshow frame delay seconds