Daubréelite

• Daubreelith

Daubréelith (also Daubreelith or English Daubreelite ) is a very rare occurring mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in the cubic crystal system with the chemical composition Fe2 Cr3 2 S4 and developed massive, flaky or platy aggregates in black color.

Etymology and history

Daubréelith named after the French meteorite researcher Gabriel Auguste Daubree ( 1814-1896 ). First described it in 1876 in the American Journal of Science.

Classification

In the now outdated but still in use 8th edition of the mineral classification by Strunz the Daubréelith belonged to the mineral class of " sulfides and sulfosalts " and then to the Department of " sulfides with the molar ratio of metal: sulfur, selenium, tellurium <1: 1 " where he along with Bornhardtit, Cadmoindit, Carrollite, Fletcherit, Florensovit, greigite, Indit, Kalininit, linnaeite, Polydymit, Siegenit, Trüstedtit, Tyrrellit and Violarit the independent " Lineitgruppe " with the system no. II/D.01 formed.

The 9th edition valid since 2001 and of the International Mineralogical Association (IMA ) used the Strunz'schen Mineral classification assigns the Daubréelith in the class of " sulfides and sulfosalts " and there in the department of " metal sulfides with M: S = 3: 4 and 2: 3 ". This division, however, is further subdivided by the exact molar ratio, so that the mineral according to its composition in the subsection "M: S = 3: 4" is to find where it, along with Bornhardtit, Cadmoindit, Carrollite, Cuproiridsit, Cuprorhodsit, Ferrorhodsit Fletcherit, Florensovit, greigite, Indit, Kalininit, linnaeite, Malanit, Polydymit, Siegenit, Trüstedtit, Tyrrellit, Violarit and Xingzhongit the " Linneitgruppe " with the system no. 2.DA.05 forms.

The mainly common in English-speaking classification of minerals according to Dana assigns the Daubréelith into the class of " sulfides and sulfosalts " and there in the department of " sulfide minerals ." He is also a member of the " Linneitgruppe " with the system no. 02:10:01 and the other members Bornhardtit, Cadmoindit, Carrollite, Cuproiridsit, Cuprorhodsit, Ferrorhodsit, Fletcherit, Florensovit, greigite, Indit, Kalininit, linnaeite, Malanit, Polydymit, Siegenit, Trüstedtit, Tyrrellit and Violarit within the subdivision " sulfides - including selenides and tellurides - with the composition AmBnXp, with (m n): p = 3: 4 to find. "

Education and Locations

Daubréelith is found in small quantities in nickel-iron meteorites, also included in the meteoritic minerals kamacite and troilite. Other accompanying minerals can be Alabandin, enstatite, graphite, plagioclase and schreibersite.

Overall Daubréelith has so far (as of 2011). Detected at 34 localities, including, inter alia in the following meteorites: ALH 84001 in Antarctica, Mundrabilla meteorite in Australia, Neuschwanstein ( meteorite ) in Germany, bustee meteorite at Gorakhpur in India, Allende ( meteorite ) in Coahuila (Mexico), Gibeon meteorite and meteorite Hoba in Namibia, Mayo Belwa in the Nigerian state of Adamawa, Muonionalusta meteorite in the Swedish municipality of Pajala and in the Canyon Diablo meteorite impact craters of Newporte in North Dakota and Norton County in the United States.

On the moon, it was found in the Hadley Rille in Mare Imbrium (Apollo 15 mission ).

Crystal structure

Daubréelith crystallizes in the space group Fd3m cubic ( Raumgruppen-Nr. 227 ) with the lattice parameters a = 9.97 Å, and eight formula units per unit cell.