Oregonite

Oregonit is a very rarely occurring mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in the hexagonal crystal system with the composition FeNi2As2, is so chemically seen a nickel - iron arsenide, which previously could only be found in the form of fine-grained gravel to about 0.5 mm in size with a smooth, brown crust.

Etymology and history

Was first discovered Oregonit on Josephine Creek in Josephine County in the U.S. state of Oregon and described in 1959 by Paul Ramdohr and Margaret Schmitt, who named the mineral after the state of Oregon.

Classification

In the now outdated but still in use 8th edition of the mineral classification by Strunz the Oregonit belonged to the mineral class of " sulfides and sulfosalts " and then to the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 formed a distinct group with Heazlewoodite, Laflammeit, parkerite, Rhodplumsit and shandite.

The 9th edition used since 2001 and valid by the International Mineralogical Association (IMA ) of the Strunz'schen Mineral classification assigns the Oregonit also in the class of " sulfides and sulfosalts " and there in the department of " alloys and alloy- like compounds " one. This division, however, is further subdivided according to the conditions prevailing in the interconnect metals, so that the mineral is found according to its composition in the subsection " nickel ( Ni) semi-metal compounds ", where it forms the unnamed group 2.AB.20 the only member.

The classification of minerals according to Dana assigns the Oregonit in the class of " sulfides and sulfosalts " and then in the Department of " sulfide minerals ." Here he is the only member of the unnamed group 02:05:04 within the subdivision " 02:05 sulfides - tellurides and selenides, including - with the composition AmBnXp, with (m n): p = 3:2 " to find.

Education and Locations

Oregonit forms in clinochlore and switchbacks. Accompanying minerals include bornite, chalcopyrite, chromite, molybdenite, and native copper.

So far (as of 2011) could be detected Oregonit fewer than 10 archaeological sites. These include, in addition to its type locality Josephine Creek in the State of Oregon nor the " Alexo Mine" at Dundonald in the Cochrane District in Canada, " Skouriotissa Mine" at Skouriotissa in the Nicosia District of Cyprus, Ferrieres -sur- Sichon in the French department Allier, Allchar the Macedonian district Roszdan and on Chirynaisky massif in the Koryak Mountains on the Kamchatka Peninsula in Russia.

Crystal structure

Oregonit crystallizes isotypic with the hexagonal crystal system Heazlewoodite ( the space group has not been determined in detail ) with the lattice parameters a = 6.083 Å and c = 7.130 Å and three formula units per unit cell.