Linnaeite
Linnaeite, also known as linnaeite, Linnaeit or under his name cobalt mining gravel is a mineral from the mineral class of " sulfides and sulfosalts ," which can be abundant in various localities in part, but overall is not widespread.
Linnaeite crystallizes in the cubic crystal system with the chemical composition of Co2 Co23 S4 and forms opaque crystals of octahedral habit mostly, but also granular to massive mineral aggregates from light gray to steel gray color with gray black stroke color. The crystal faces fresh mineral samples exhibit a metallic luster. After some time, they can start but dull or colorful color.
With Polydymit linnaeite forms a mixed batch, in which cobalt is replaced by nickel.
Special Features
Before the blowpipe linnaeite separates sulfurous acid, roasted to a magnetic ball forms. In nitric acid dissolves the mineral, sulfur being deposited.
Etymology and history
The mineral was found in 1832 by François Sulpice Beudant in the type locality, the Bastnäs mine in Skinnskatteberg, Västmanland in Sweden and initially called Koboldin. From this mine, in many rare earth minerals are found, inter alia, are the ores from which the elements cerium and lanthanum were first extracted.
The present name was given in 1845 by Wilhelm Ritter von Haidinger after the Swedish botanist and taxonomist Carl Linnaeus.
Classification
In the now outdated but still in use 8th edition of the mineral classification by Strunz the linnaeite belonged to the mineral class of " sulfides and sulfosalts " and then to the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, Daubréelith, Fletcherit, Florensovit, greigite, Indit, Kalininit, Polydymit, Siegenit, Trüstedtit, Tyrrellit and Violarit named after him " Linneitgruppe " 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 linnaeite also in the class of " sulfides and sulfosalts ," there, however, in the new department of " metal sulfides with M: S = 3: 4 and 2: 3 ". This 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, Daubréelith, Ferrorhodsit Fletcherit, Florensovit, greigite, Indit, Kalininit, Malanit, Polydymit, Siegenit, Trüstedtit, Tyrrellit, Violarit and Xingzhongit still existing " Linneitgruppe " with the system no. 2.DA.05 forms.
The mainly common in English-speaking classification of minerals according to Dana assigns the linnaeite into the class of " sulfides and sulfosalts " and there in the department of " sulfide minerals ." He is also named as the " Linneitgruppe ( Isometric: Fd3m ) " with the system no. 02:10:01 and the other members Bornhardtit, Cadmoindit, Carrollite, Cuproiridsit, Cuprorhodsit, Daubréelith, Ferrorhodsit, Fletcherit, Florensovit, greigite, Indit, Kalininit, 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 find ".
Modifications and varieties
There is known a gold-bearing variety of Linneits. This is so far only known from a Fund in the Santa Fe mine in the Mexican state of Chiapas.
Education and Locations
Linnaeite forms along with other nickel and cobalt sulphides in veins under hydrothermal conditions. It is associated with chalcopyrite, pyrrhotite, millerite, bismuthinite, Gersdorffite, Carrollite, Cattierit, Ullmannite, marcasite, pyrite, galena and sphalerite.
Worldwide, linnaeite so far (as of 2011) are detected at around 200 localities. In addition to the type locality Bastnäs in Västmanland we found the mineral in Sweden nor in Smedsbo in Dalarna, Vittangi ( Kiruna municipality ) in Lapland, Tunaberg ( Nyköping) in Södermanland, and are found in several places in Småland and Västmanland.
In Germany linnaeite especially in the Black Forest in Baden -Württemberg, in Lower Bavaria and the Upper Palatinate, in Bellnhausen ( Glad Bach) in Hesse, the Rammelsberg in Saxony, in the Sauerland region and winner of the country, at several places in Rhineland -Palatinate, in the Saxon Erzgebirge and in Ronneburg found in Thuringia.
In Austria, the mineral is found on the Erzberg hut in Carinthia, Stubach in Salzburg and at several locations in Styria and Tyrol. In Switzerland linnaeite occurred among others in the Murg Valley in the canton of Glarus, in Trun GR in Graubünden, Molino TI in Canton Ticino and Ayer (Val d' Anniviers ) in the canton of Valais on.
Known for its well-trained crystals with up to three centimeters in diameter is the Kilembe mine in the Kingdom of Toro in Uganda.
More Locations are Afghanistan, Argentina, Australia, Azerbaijan, Bolivia, Bulgaria, Chile, China, Finland, France, Ghana, India, Italy, Canada, Kazakhstan, the Democratic Republic of Congo, Croatia, Madagascar, Mexico, Morocco, Namibia, Netherlands, Norway, Poland, Romania, Russia, Zambia, Zimbabwe, Slovakia, Spain, South Africa, Czech Republic, Ukraine, the United Kingdom ( UK), the United States of America (USA).
Crystal structure
Linnaeite crystallizes in the cubic crystal system in the space group Fd3m ( Raumgruppen-Nr. 227 ) with the lattice parameters a = 9.43 Å, and eight formula units per unit cell. The structure corresponds to a spinel structure is substituted with sulfur in the oxygen ( Thiospinell ).
Use
Linnaeite found in local accumulation as Cobalterz use.