Centennialite

CaCu3Cl2(OH)6 · nH2O (n ~ 0.7)
IMA status
  • Approved
IMA symbol
Cte
IMA approved
2013
Also known as
  • Centennialiet
  • IMA2013-110

Where it forms, where it's found

Geological setting

A secondary alteration phase, formed due to interaction of supergene Cu mineralization with acid water

Type locality
Centennial Mine
  1. Centennial Heights
  2. Calumet Township
  3. Houghton County
  4. Michigan
  5. USA

47.2583°, -88.4286°

1recorded occurrences
Source · OpenStreetMap

Physical

Colour
Pale to azure blue

Crystallography

Crystal system
Trigonal
Space group
#97
Cell parameters
a = 6.6606(9) Å · c = 5.8004(8) Å
Unit cell volume
222.85 ų
Z
1
Morphology

Botryoidal encrustations.

Type-locality form

Encrustations (often botryoidal)

Synonyms

  • Centennialiet
  • IMA2013-110

In other languages

German
Centennialit · IMA 2013-110
Italian
centennialite

Classification

Strunz
10th ed.

3.DA

  • 3HalidesClass
  • 3.DOxyhalides, hydroxyhalides and related double halidesDivision
  • 3.DAWith Cu, etc., without PbGroup
  • 3.DACentennialiteSpecies

Literature, links & citation

Citations
  1. 2002Brandes, P.T., Robinson, G.W. (2002) A Preliminary Study of Calumetite and Other Copper Chloride Mineralization on the Keweenaw Peninsula, Michigan. Unpublished MSc thesis, Michigan Technological University, USA.
  2. 2014Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2014) New minerals and nomenclature modifications approved in 2014, CNMNC Newsletter No 19. Mineralogical Magazine, 78 (1) 165-170 doi:10.1180/minmag.2014.078.1.12DOI: 10.1180/minmag.2014.078.1.12
  3. 2016Sun, W., Huang, Y.X., Pan, Y., Mi, J.X. (2016) Synthesis and magnetic properties of centennialite: a new S= ½ Kagomé antiferromagnet and comparison with herbertsmithite and kapellasite. Physics and Chemistry of Minerals: 43: 127-136.
  4. 2017Crichton, Wilson A., Müller, Harald (2017) Centennialite, CaCu3(OH)6Cl2.nH2O, n ≈ 0.7, a new kapellasite-like species, and a reassessment of calumetite. Mineralogical Magazine, 81 (5) 1105-1124 doi:10.1180/minmag.2016.080.157DOI: 10.1180/minmag.2016.080.157
  5. 2020(2020) Centennialite. Handbook of Mineralogy. Mineralogical Society of America
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Centennialite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/centennialite-46033},
  note      = {Accessed 2026-05-11}
}