Hollandite from Midcontinent Rift, USA
USA | |
| Heinrich, E. W., Robinson, George Willard (2004) Mineralogy of Michigan (2nd ed.) A.E. Seaman Mineral Museum and Michigan Technological University. 252pp. |
| Morris Jr., T. (1983) Michigan Mineralogy: A Locality Index. Rocks & Minerals: 58(3): 111. |
| Robinson, G. & G. LaBerge (2013) Minerals of the Lake Superior Iron Ranges: A. E. Seaman Mineral Museum: Michigan Technological University, 52 p. |
| Robinson, G. & G. LaBerge (2013) Minerals of the Lake Superior Iron Ranges: A. E. Seaman Mineral Museum: Michigan Technological University, 52 p. |
Manganese Mine, Copper Harbor, Grant Township, Keweenaw County, Michigan, USA