Connellite

Connellite is a rarely occurring mineral from the mineral class of " halides ". It crystallizes in the hexagonal crystal system with the chemical composition Cu19 [ Cl4 (OH ) 32 | SO4 ] • 2H2O and usually develops dense fibrillar groups to acicular, radialstrahliger crystal tufts of a few millimeters in size, which are usually stretched and streaked by. Also massive aggregates and crusty coatings from Connellite are known. The color varies from light to blue green.

Connellite forms a mixed batch with Buttgenbachit.

Etymology and history

Was first found Connellite 1842 in the " Providence Mine" at Carbis Bay / Lelant in the English county of Cornwall and described by Rashleigh, who named the mineral after Arthur Connell ( 1794-1863 ), a Scottish chemist, who investigated the mineral first.

Classification

In the now outdated but still in use 8th edition of the mineral classification by Strunz the Connellite belonged to the mineral class of " halides " and then to the Department of " oxyhalides ", where he formed a distinct group with Buttgenbachit, Claringbullit, Gordait, Khaidarkanit and Simonkolleit.

The 9th edition valid since 2001 and of the International Mineralogical Association (IMA ) used the Strunz'schen Mineral classification assigns the Connellite in the class of " halides " and there in the department of " oxyhalides, hydroxyhalides and related double halides " a. This division, however, is further subdivided by the dominant cation in the compound, so that the mineral is found according to its composition in the subsection "With Cu, etc., without Pb" where it only together with Buttgenbachit the unnamed group 3 DA.25 forms.

The mostly commonly used in English-speaking classification of minerals according to Dana assigns the Connellite contrast, in the class of sulfates and there in the department of " water -containing sulfates with hydroxyl or halogen" one. Here the mineral is the only member of the unnamed group 31.01.01 within the subdivision " water -containing sulfates with hydroxyl or halogen, and the general formula ( A B2 ) m ( XO4 ) PZQ • x (H2O), with the molar ratio of m: p> 6:1 to find. "

Education and Locations

Connellite forms as a secondary mineral in the oxidation zone of copper deposits. There it is mostly associated with Atacamit, azurite, Botallackit, cuprite, Langit, malachite and Spangolith.

Worldwide, Connellite so far (as of 2010) are detected at around 210 localities, so including in Algeria, Argentina, Australia, Belgium, Bolivia, Chile, France, Germany, Greece, Greenland, Ireland, Italy, Japan, the Democratic Republic of Congo, Morocco, Namibia, New Zealand, Austria, Portugal, Spain, South Africa, Czech Republic, Hungary, Uzbekistan, the United Kingdom ( UK ) and the United States (USA).

Crystal structure

Connellite crystallized hexagonal space group P63/mmc with lattice parameters a = 15.787 Å and c = 9.102 Å and two formula units per unit cell.