Alabandite
Alabandin, also known by the mining titles Manga aperture, Manga gloss, Braunstein aperture and brown stone pebbles, is a mineral from the mineral class of " sulfides and sulfosalts ," which can be abundant in various localities in part, is but overall not widespread.
Alabandin crystallizes in the cubic crystal system with the chemical composition of α - MnS or short MnS is therefore chemical seen a manganese (II ) sulfide, the most würfeliger in nature in the form or octahedral crystals, but also grained to massive aggregates in black, steel-gray or brownish-black color is found.
Special Features
The mineral is usually opaque and shows on the crystal surfaces only fresh metallic to semi -metallic luster. After some time it runs to brownish black and matt. On the dash panel leaves Alabandin a green line.
Alabandin is before the blowtorch difficult fusible.
Etymology and history
Alabandin was named after his alleged first locality Alabanda in Turkey. In fact, the mineral was, in contrast to the named also of this place almandine garnet mineral, but so far never been detected in Turkey.
Was first described in 1784 by Franz Joseph Müller Alabandin of rich stone. As a type locality is today the Romanian place Sacarîmb in Hunedoara County.
Classification
In the now outdated but still in use 8th edition of the mineral classification by Strunz the Alabandin belonged to the mineral class of " sulfides and sulfosalts " and then to the Department of " metal: sulfur, selenium, tellurium = 1:1", where he along with Altait, Clausthalite, Crerarit, galena, Keilit, Niningerit and oldhamite the unnamed group II/C.15 formed.
The valid since 2001 and used by the IMA 9th edition of the Strunz'schen Mineral classification assigns the Alabandin also in the class of " sulfides and sulfosalts ," specifically the sulfides, selenides, tellurides, arsenides, antimonides, bismuthides, Sulfarsenite, Sulfantimonite and Sulfbismuthite, and there in the department of " metal sulfides, M: S = 1: 1 ( and similar ) " a. This division, however, is now more precisely divided according to the nature of the cations involved, so that the mineral is found according to its composition in the subdivision " with tin ( Sn ), lead ( Pb ), mercury (Hg ), etc. ", where it together with Altait, Clausthalite, Crerarit, Cuboargyrit, galena, Keilit, Niningerit, oldhamite and Schapbachit the unnamed group forms 2.CD.10.
The classification of minerals according to Dana assigns the Alabandin in the class of " sulfides and sulfosalts ", There, however, in the department of " sulfide minerals ." He is a member of " Galena Group ( isometric: Fm3m ) " with the system no. 02.08.01 and the other members Clausthalite, Altait, oldhamite, Niningerit, Borovskit, Crerarit and Keilit within the sub-division of " sulfides - tellurides and selenides, including - with the composition AmBnXp, with (m n): p = 1:1".
Modifications and varieties
The compound MnS ( manganese (II ) sulfide ) is dimorphic, meaning that they occur in nature in addition to the cubic modification of Alabandin still as hexagonally crystallizing Rambergit on.
Education and Locations
Alabandin forms a hydrothermal method in vein deposits ( veins ), where it is often found in paragenesis with galena, pyrite, sphalerite, rhodochrosite, calcite and others.
Overall Alabandin has so far (as of 2011) are detected at around 230 localities. Apart from its type locality Sacarîmb where with a diameter of up to two centimeters, the biggest crystals were found, the mineral nor entered into Romania at Brad in Hunedoara County and at Roşia Montană in Alba county.
In Germany Alabandin found in the pit blessing of God in Gersdorf in the community Striegistal ( about 20 miles northwest of Freiberg ) and in the stockpile remains of Altbergbaugebietes at Berggießhübel. Another locality that Absetzerhalde at Ronneburg in Thuringia, no longer exists.
In Switzerland Alabandin has so far been found in the canton of Uri belonging municipality silenes UR only the water tunnel of the power plant Amsteg.
Other localities are Antarctica, Argentina, Armenia, Australia, Bolivia, Brazil, Bulgaria, China, Finland, France, Ghana, Greece, Greenland, India, Italy, Japan, Yemen, Canada, Mexico, Kyrgyzstan, Namibia, New Zealand, Norway, Peru, Poland, Russia, Sweden, Slovakia, South Africa, South Korea, Taiwan, Tanzania, the Czech Republic, Uzbekistan, the United Kingdom ( UK) and the United States of America (USA).
Crystal structure
Alabandin crystallizes in the cubic crystal system with space group Fm3m ( Raumgruppen-Nr. 225 ) with the lattice parameters a = 5.22 Å and four formula units per unit cell.