Aegirine

• Aegirine
• Akmit

Aegirine, also known as aegirine or Akmit, is a rarely occurring mineral from the mineral class of " silicates and Germanates ". It crystallizes in the monoclinic crystal system with the chemical composition NaFe3 [ Si2O6 ] and developed mostly long, prismatic, acicular crystals or radiating aggregates in shades of green to black.

Aegirin heard among many other minerals to the pyroxene group. With augite it forms a mixed batch. The intermediate members are called Aegirinaugit.

Etymology and history

Named after Aegir aegirine, the Norse god of the sea, as it was found for the first time in Norway. As a type locality Rundemyr apply to Nedre Eiker in the province Buskerud and located in Langesundsfjorden Låven island in the province of Vestfold.

Was first described mineral, a brownish pyroxene from Rundemyr at Nedre Eiker in the province Buskerud, 1821 by Jöns Jakob Berzelius and P. Ström, who named it after the Greek word for Akmit point, based on the most acute form of the crystals. 1835 green pyroxene was found on the island located in the Langesundsfjord Låven in the province of Vestfold and named by Berzelius after Aegir, the Norse god of the sea. When it was recognized that both samples of the same mineral species belonged to, it was decided to use the name Akmit future as a synonym of the mineral aegirine.

Occasionally Aegirin is also evidenced by the synonym Schefferit. This name, however, was assigned in 1988 by the IMA Subcommittee of a manganese-containing variety of diopside, which was discovered in the Swedish mining community Långban.

Classification

In the now outdated but still in use 8th edition of the mineral classification by Strunz the Aegirin belonged to the department of " chains and chain silicates ( inosilicates ) " where he along with augite, diopside, Esseneit, hedenbergite, jadeite, Jervisit, Johannsenite, Kanoit, Klinoenstatit, Klinoferrosilit, Kosmochlor, Namansilit, Natalyit, omphacite, Petedunnit, pigeonite and spodumene the subgroup of " clinopyroxene " with the system no. VIII/F.01 formed within the pyroxene group.

The 9th edition valid since 2001 and of the International Mineralogical Association (IMA ) used the Strunz'schen Mineral classification assigns the aegirine also included in the department's " chain and chain silicates ( inosilicates ) ". However, this is further subdivided by the type of structure of the chains, so that the mineral according to its construction in the subsection " chain and chain silicates with 2- periodic single chains Si2O6; Pyroxene family " is to find where it along with jadeite, Jervisit, Kosmochlor, Namansilith and Natalyit the group of". Na - clinopyroxene, Jadeitgruppe "with the System No. 9.DA.25 forms.

The classification of minerals according to Dana assigns the aegirine in the class of " silicates and Germanates " and there in the department of " chain silicate minerals " one. Here he is with jadeite, Namansilith, Kosmochlor, Natalyit and Jervisit in the group of " C2 / c clinopyroxene (Na - clinopyroxene ) " with the system no. 65.01.03c within the subdivision " chain silicates: Simple unbranched chains, W = 1 with chains P = 2" to find.

Modifications and varieties

A manganese-containing variety of aegirine is called urbanité.

Education and Locations

Aegirine forms in igneous rocks such as syenite, carbonatite, but also in basic granites. Accompanying minerals include Aenigmatit, Apophyllite, Arfvedsonite, Astrophyllite, Catapleiit, eudialyte, various potassic feldspars, nepheline, riebeckite and Serandit.

Worldwide, aegirine so far (as of 2011) are detected at around 700 localities. These include the localities Malosa and Songwe in Malawi as well as the environment of the Langesundsfjord, where well-trained, prismatic crystals could be up to 15 or 30 cm size have been found. Furthermore can find good Aegirinkristalle also at Mont Saint- Hilaire in Quebec and elsewhere in Canada and in the Kola Peninsula and many other regions in Russia.

In addition to its Type localities Rundemyr ( Nedre Eiker, Buskerud ) and Låven ( Vestfold ) still occurred Aegirin in Norway in many other regions of the provinces of Nord-Trøndelag, Oppland, Oslo and Telemark.

In Germany Aegirin could, among other things in several regions of the Black Forest, the emperor chair and in the Odenwald Baden -Württemberg; on Teichel mountain and Bad Berneck in Bavaria; at Pearl Hardt King Winter and Wachtberglifte ( High Castle ) in North Rhine -Westphalia; on Ettringer Bellerberg at Ettringen in Rhineland -Palatinate and in Brunsbuttel, Schwedeneck ( Stohl ) and Great Pampau be found in Schleswig -Holstein.

In Austria, the mineral is found on Pauliberg in Burgenland; Pleschitzkogel in Carinthia; Schlossberg and Puchberg am Schneeberg ( in Lower Austria ); on Einberg and in the " Haagen Mine" at Abtenau and at the grave stream and in the Grubach at Golling on the Salzach River in Salzburg; in the gypsum mine near Bad Aussee in Styria; on Tarntaler heads in Tyrol and Vorarlberg in Dalaas.

In Switzerland Aegirin previously occurred only in Ausserferrera and Val Starlera in the Upper Rhine Valley and the Val Lumnezia in the canton of Grisons.

More Locations are Afghanistan, Algeria, Angola, Antarctica, Argentina, Armenia, Ethiopia, Australia, Bolivia, Brazil, Bulgaria, Chile, China, France, French Polynesia, Greece, several regions in Greenland, Guatemala, Guinea, Guyana, Honduras, India, several regions in Italy, Japan, Cameroon, on the Channel Island of jersey, Kazakhstan, Kenya, Kyrgyzstan, the Democratic Republic of Congo, Libya, Madagascar, Mali, Morocco, Macedonia, Mexico, Mongolia, Myanmar, Namibia, New Zealand, Niger, Nigeria, North Korea, Pakistan, Paraguay, Peru, Poland, Portugal, Reunion, Romania, Saint Helena, Ascension and Tristan da Cunha, Zambia, Saudi Arabia, Sweden, Slovakia, Somalia, Spain, South Africa, Tajikistan, Tanzania, Czech Republic, Turkey, Uganda, Ukraine, Hungary, Venezuela, the United Kingdom, many regions in the United States of America ( USA), Vietnam and Belarus.

Crystal structure

Aegirine crystallized in the monoclinic space group C2 / c ( Raumgruppen-Nr. 15) with the lattice parameters a = 9.66 Å; b = 8.80 Å; c = 5.29 Å and 107.4 ° and β = 4 formula units per unit cell.