Connellite

(repeating unit)Cu19(OH)32(SO4)Cl4·3H2OIMA symbolCnl[1]Strunz classification3.DA.25Crystal systemHexagonalCrystal classDihexagonal dipyramidal (6/mmm)
H-M symbol: (6/m 2/m 2/m)Space groupP63/mmcUnit cella = 15.78 Å, c = 9.10 Å; Z = 1IdentificationColorAzure blue, blue greenCrystal habitClusters of divergent acicular crystals, fibrous, crustsCleavageNoneFractureSplinteryTenacityBrittleMohs scale hardness3LusterVitreousStreakPale green-blueDiaphaneityTranslucentSpecific gravity3.36 to 3.41Optical propertiesUniaxial (+)Refractive indexnω = 1.724 – 1.746 nε = 1.738 – 1.758Birefringenceδ = 0.014References[2][3][4][5]

Connellite is a rare mineral species, a hydrous copper chloro-sulfate,[6] Cu19(OH)32(SO4)Cl4·3H2O, crystallizing in the hexagonal system. It occurs as tufts of very delicate acicular crystals of a fine blue color, and is associated with other copper minerals of secondary origin, such as cuprite and malachite. Its occurrence in Cornwall, England, was noted by Philip Rashleigh in 1802, and it was first examined chemically by Prof Arthur Connell FRSE in 1847, after whom it is named.[6]

The type locality is Wheal Providence at Carbis Bay in Cornwall.[4] Outside Cornwall it has been found in over 200 locations worldwide including Namaqualand in South Africa and at Bisbee, Arizona (US).[4]

Connellite crystal structure: Color code: Cu: copper, S: olive, O: red, Cl: green; Cell: magenta

References

  • flagCornwall portal
  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Connellite Mineralienatlas
  3. ^ Connellite in the Handbook of Mineralogy
  4. ^ a b c Connellite: Connellite mineral information on Mindat.org
  5. ^ Connellite data on Webmineral
  6. ^ a b  One or more of the preceding sentences incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Connellite". Encyclopædia Britannica. Vol. 6 (11th ed.). Cambridge University Press. p. 963.


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