Centennial #6 was the last of the mines near Calumet to be abandoned and allowed to fill with water.  Why do the mines fill with water? This mine was a conglomerate ore body and it followed the dip deep into levels thousands of feet from the surface.

Centennial #6 Minerals

Bob's Rock Shop

Mineralogy Database

Mineralogical Society of America - Mineralogy, Petrology and Crystallography

WebElements Periodic Table of the Elements

Michigan Copper Mines