Aegirine
| Aegirine | |
|---|---|
 |
|
| General and classification | |
| other names |
|
| chemical formula | NaFe 3+ [Si 2 O 6 ] |
|
Mineral class (and possibly department) |
Silicates and germanates - chain silicates |
|
System no. to Strunz and to Dana |
9.DA.25 ( 8th edition : VIII / D.01c) 65.01.03c.02 |
| Crystallographic Data | |
| Crystal system | monoclinic |
| Crystal class ; symbol | monoclinic prismatic; 2 / m |
| Space group | C 2 / c (No. 15) |
| Lattice parameters |
a = 9.66 Å ; b = 8.80 Å; c = 5.29 Å β = 107.4 ° |
| Formula units | Z = 4 |
| Physical Properties | |
| Mohs hardness | 6th |
| Density (g / cm 3 ) | measured: 3.50 to 3.60; calculated: 3.576 |
| Cleavage | good after {110}; Segregation after {100} |
| Break ; Tenacity | uneven |
| colour | dark green to black green |
| Line color | light yellow-gray |
| transparency | translucent to opaque |
| shine | Glass gloss to matt |
| Crystal optics | |
| Refractive indices |
n α = 1.720 to 1.778 n β = 1.740 to 1.819 n γ = 1.757 to 1.839 |
| Birefringence | δ = 0.037 to 0.061 |
| Optical character | biaxial negative |
| Axis angle | 2V = measured: 60 to 90 °; calculated: 68 to 84 ° |
| Pleochroism | visible: X = emerald green to dark green; Y = grass green to dark green, yellow; Z = brownish green to green, yellowish brown to yellow |
Aegirine , also known as aegirine or synonym Akmit , is a frequently occurring mineral from the pyroxene group within the mineral class of " silicates and germanates " with the idealized chemical composition NaFe 3+ [Si 2 O 6 ] and thus, chemically speaking, a sodium - iron- silicate . Structurally, aegirine belongs to the chain and band silicates .
Aegirine crystallizes in the monoclinic crystal system and usually develops long, needle-like to prismatic crystals with a glass-like sheen on the surfaces. Often these are also connected to radial mineral aggregates . The translucent to opaque crystals are dark green to black green in color. However, Aegirin leaves a light yellow-gray line on the marking board .
Etymology and history
Aegirin was named after Aegir (also Ægir ), the Nordic god of the sea, as the mineral was first found in Norway . The type locality is Rundemyr near Nedre Eiker in the province of Viken and the island of Låven in the Langesundsfjorden in the province of Vestfold .
The mineral, a brownish pyroxene from Rundemyr near Nedre Eiker in the province of Viken , was first described in 1821 by Jöns Jakob Berzelius and P. Ström, who named it after the Greek word Akmit for point, based on the mostly pointed shape of the crystals. In 1835 a green pyrox was found on the island of Låven in the Langesundsfjord in the province of Vestfold and named by Berzelius after Aegir , the Nordic god of the sea. When it was realized that both samples belonged to the same type of mineral, it was decided to use the name Akmit as a synonym for the mineral aegirine in the future.
Occasionally, aegirine is also used with the synonym Schefferit . However, this name was assigned by the IMA Subcommittee in 1988 to a manganese-containing variety of diopside that was discovered in the Swedish mining community of Långban .
classification
Already in the outdated 8th edition of the mineral system according to Strunz , the aegirin belonged to the mineral class of "silicates and germanates" and there to the department of " chain and band silicates (inosilicates) ", where together with jadeite and cosmochlor it belongs to the "jadeite series" the system no. VIII / D.01c within the group of “Klinopyroxene. Monocline prismatic ”.
In the Lapis mineral directory according to Stefan Weiß, which, out of consideration for private collectors and institutional collections, is still based on this old form of Karl Hugo Strunz's system , the mineral was given the system and mineral number. VIII / F.01-140 . In the "Lapis Classification" this also corresponds to the "chain and chain silicates" department where Aegirin together with pyroxene , Aegirin-pyroxene ( aegirine-augite ), Davisit , diopside , Esseneit , Grossmanit , Hedenbergit , jadeite, Jervisit , Johannsenite , kanoite , Klinoenstatite , Klinoferrosilit , Kosmochlor , Kushiroit , Namansilit , Natalyit , Omphacit , Petedunnit , Pigeonit , Spodumene and Tissintit form the subgroup of the "Klinopyroxene" within the " Pyroxene Group " ranging from F.01 to F.02 (status 2018).
The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and was updated by the International Mineralogical Association (IMA) until 2009, also classifies the aegirin in the category of "chain and band silicates (inosilicates)". However, this is further subdivided according to the structure of the chains, so that the mineral is classified in the sub-section “Chain and band silicates with 2-periodic single chains Si 2 O 6 ; Pyroxene family "is to be found, where together with jadeite, jervisite, cosmochlor, namansilite and natalyite the group of the" Na-Klinopyroxene, jadeite group "with the system no. 9.DA.25 forms.
The systematics of minerals according to Dana also assigns the aegirin to the class of "silicates and germanates" and there in the department of "chain silicate minerals". Here he is together with Jadeite, Namansilith, Kosmochlor, Natalyit and Jervisit in the group of " C2 / c Klinopyroxene (Na-Klinopyroxene) " with the system no. 65.01.03c within the sub-section “Chain Silicates: Simple unbranched chains, W = 1 with chains P = 2”.
Chemism
The idealized (theoretical) composition of aegirine (NaFe 3+ Si 2 O 6 ) consists of 9.95% sodium (Na), 24.18% iron (Fe), 24.32% silicon (Si) and 41.56% Oxygen (O).
However, due to mixed crystal formation with hedenbergite (CaFe 2+ Si 2 O 6 ), part of the sodium is often represented ( substituted ) by calcium . In addition, due to Diadochie, proportions of magnesium , titanium , vanadium as well as low contents of rare earths , beryllium , zirconium , thorium and manganese can be present.
Crystal structure
Aegirine crystallizes monoclinically in the space group C 2 / c (space group no. 15) with the lattice parameters a = 9.66 Å ; b = 8.80 Å; c = 5.29 Å and β = 107.4 ° and 4 formula units per unit cell .
Modifications and varieties
A variety of aegirine containing manganese is known as urbanite .
Education and Locations
Aegirine forms in igneous rocks such as syenite , carbonatite , but also in basic granites . Accompanying minerals include aenigmatite , apophyllite , arfvedsonite , astrophyllite , catapleiite , eudialyte , various potassium-containing feldspar , nepheline , riebeckite and sérandite .
As a frequent mineral formation, aegirine can be found at many sites, with around 1200 sites documented so far (as of 2020).
In addition to its type localities Rundemyr (Nedre Eiker, Viken) and Låven (Vestfold og Telemark), Aegirin performed in many other regions of the provinces of Trøndelag , Oppland , Oslo and Telemark in Norway .
In Germany, Aegirin was able to work in several regions of the Black Forest , in the Kaiserstuhl and in the Odenwald in Baden-Württemberg; at Teichelberg and at Bad Berneck in the Fichtelgebirge in Bavaria; near Perlenhardt - Königswinter and Wachtberg (Hohenburg) in North Rhine-Westphalia; at Ettringer Bellerberg near Ettringen in Rhineland-Palatinate and near Brunsbüttel , Schwedeneck (Stohl) and Groß Pampau in Schleswig-Holstein.
In Austria the mineral was found on the Pauliberg in Burgenland; Pleschitzkogel in Carinthia ; Schlossberg and Puchberg am Schneeberg (in Lower Austria); on Einberg and in the "Haagen pit" near Abtenau as well as on Grabenbach and Grubach near Golling an der Salzach in Salzburg; in the gypsum mine near Bad Aussee in Styria; on the Tarntaler Köpf in Tyrol and near Dalaas in Vorarlberg.
In Switzerland, aegirin has only performed in Ausserferrera and in Val Starlera in the Hinterrheintal and in Val Lumnezia in the canton of Graubünden .
Also known due to extraordinary aegirin finds are Mount Malosa near Zomba in Malawi and the area around the Langesundsfjord in the former Norwegian province of Vestfold , where well-formed, prismatic crystals up to 15 and 30 cm in size could be found. Furthermore, good aegirine crystals can also be found on Mont Saint-Hilaire in Québec and other regions in Canada as well as on the Kola Peninsula and many other regions in Russia .
Other 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 , the Channel Island Jersey , Kazakhstan , Kenya , Kyrgyzstan , the Democratic Republic of the Congo , Libya , Madagascar , Mali , Morocco , Mexico , Mongolia , Myanmar , Namibia , New Zealand , Niger , Nigeria , North Korea , North Macedonia , Pakistan , Paraguay , Peru , Poland , Portugal , Réunion , Romania , St. Helena, Ascension and Tristan da Cunha , Zambia , Saudi Arabia , Sweden , Slovakia , Somalia , Spain , South Africa , Tajikistan , Tanzania , Czech Republic , Turkey , Uganda , Ukraine , Hungary , Venezuela , in the United Kingdom , many regions in the United States of America (USA), Vietnam and Belarus .
See also
literature
- Martin Okrusch, Siegfried Matthes: Mineralogy. An introduction to special mineralogy, petrology and geology . 7th, completely revised and updated edition. Springer, Berlin [a. a.] 2005, ISBN 3-540-23812-3 , pp. 95 .
Web links
- Mineral Atlas: Aegirine (Wiki)
- Aegirine search results. In: rruff.info. Database of Raman spectroscopy, X-ray diffraction and chemistry of minerals (RRUFF), accessed January 12, 2020 .
- American-Mineralogist-Crystal-Structure-Database - Aegirine. In: rruff.geo.arizona.edu. Retrieved January 12, 2020 .
Individual evidence
- ↑ a b c d e Hugo Strunz , Ernest H. Nickel : Strunz Mineralogical Tables. Chemical-structural Mineral Classification System . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p. 621 .
- ↑ Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: November 2019. (PDF 1720 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, November 2019, accessed January 12, 2020 .
- ^ A b David Barthelmy: Aegirine Mineral Data. In: webmineral.com. Retrieved January 12, 2020 .
- ↑ a b c Aegirine . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 ( handbookofmineralogy.org [PDF; 80 kB ; accessed on January 12, 2020]).
- ↑ a b c d e f Aegirine. In: mindat.org. Hudson Institute of Mineralogy, accessed January 12, 2020 .
- ↑ gates Prestvik, Calvin G. Barnes: A new occurrence of Aegirine in Norway . In: Norwegian Journal of Geology . tape 87 , 2007, ISSN 0029-196X , p. 451–456 ( foreninger.uio.no [PDF; 1,2 MB ; accessed on January 12, 2020]).
- ↑ Schefferite. In: mindat.org. Hudson Institute of Mineralogy, accessed January 12, 2020 .
- ↑ a b Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties. Status 03/2018 . 7th, completely revised and supplemented edition. Weise, Munich 2018, ISBN 978-3-921656-83-9 .
- ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1816 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed January 12, 2020 .
- ↑ Hans Jürgen Rösler : Textbook of Mineralogy . 4th revised and expanded edition. German publishing house for basic industry (VEB), Leipzig 1987, ISBN 3-342-00288-3 , p. 525 .
- ↑ Localities for Aegirine. In: mindat.org. Hudson Institute of Mineralogy, accessed January 12, 2020 .
- ↑ Petr Korbel, Milan Novák: Mineral Encyclopedia (= Dörfler Natur ). Edition Dörfler im Nebel-Verlag, Eggolsheim 2002, ISBN 978-3-89555-076-8 , p. 235 .
- ↑ List of locations for aegirine in the Mineralienatlas and Mindat , accessed on January 12, 2020.