Home > American Minerals – January 11 > MS1998 Centennialite (IMA2013-110) with Calumetite

Centennialite (IMA2013-110) with Calumetite


Centennialite and calumetite are both hydrous calcium copper chlorides. Williams (1963) named calumetite after Calumet, a mining town on Michigan's Keweenaw Peninsula. When re-investigating calumetite, Crichton & Müller (2017) proposed a new ideal formula for calumetite and also characterized an associated new mineral, which they named centennialite. The mineral name centennialite recalls the Centennial mine, which is the mine located at Calumet. This specimen comes from the type locality for both calumetite and centennialite.

Calumetite and centennialite form blue-green crusts on native copper which protrudes from conglomerate matrix. Our X-ray diffraction study of this specimen confirms the presence of centennialite. A vintage label from the Morris Museum also accompanies the specimen.

Price: $300

Item code: MS1998

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