Hagendorfite

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Hagendorfite
Hagendorfite-sea78a.jpg
Hagendorfite from the Siglo Veinte Mine, Llallagua , Potosí, Bolivia (size: 1.8 × 1.4 × 0.9 cm)
General and classification
chemical formula NaCaMnFe 2+ 2 [PO 4 ] 3
Mineral class
(and possibly department)
Phosphates, arsenates and vanadates
System no. to Strunz
and to Dana
8.AC.10 ( 8th edition : VII / A.06)
02.38.03.02
Crystallographic Data
Crystal system monoclinic
Crystal class ; symbol monoclinic prismatic; 2 / m
Space group I 2 / a (No. 15, position 3)Template: room group / 15.3
Lattice parameters a  = 10.93  Å ; b  = 12.59 Å; c  = 6.51 Å
β  = 98.0 °
Formula units Z  = 4
Physical Properties
Mohs hardness 3.5 to 4.5
Density (g / cm 3 ) measured: 3.71; calculated: [3.84]
Cleavage good after {001}, indistinct after {110}
Break ; Tenacity uneven; brittle
colour dark green, greenish black
Line color gray-green
transparency translucent
shine Resin or greasy gloss to weak glass gloss
Crystal optics
Refractive indices n α  = 1.708 to 1.735
n β  = 1.742
n γ  = 1.722 to 1.745
Birefringence δ = 0.014
Optical character biaxial negative
Axis angle 2V = 68 ° to 70 ° (measured), 66 ° (calculated)
Pleochroism Visible to strong: X = brownish to yellowish green, Z = blue-green to grass-green

Hagendorfite is a rarely occurring mineral from the mineral class of "phosphates, arsenates and vanadates" with the chemical formula NaCaMnFe 2+ 2 [PO 4 ] 3 , so it is chemically a sodium - calcium - manganese - iron - phosphate .

Hagendorfite crystallizes in a monoclinic crystal system , but only very rarely develops translucent crystals up to four millimeters in size that are visible to the naked eye . Usually it is found in the form of coarse, late masses from dark green to black-green in color.

Together with Varulith , Hagendorfit forms a complete mixed crystal series.

Etymology and history

Hagendorfite was first discovered in the Corneliaschacht of Hagendorf -Süd in the district of Neustadt an der Waldnaab in the Upper Palatinate and described in 1954 by Karl Hugo Strunz , who named the mineral after its type locality .

The type material of the mineral is at Harvard University in Cambridge (Massachusetts) in the USA under the catalog no. 107297 kept.

classification

Already in the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , the hagendorfite belonged to the mineral class of "phosphates, arsenates and vanadates" and there to the division of "anhydrous phosphates [PO 4 ] 3− , without foreign anions ", where he together with Alluaudit , Arseniopleit , Bobfergusonit , Ferroalluaudit , Ferrohagendorfit , Ferrorosemaryit , Ferrowyllieit , Karyinit , Maghagendorfit , Qingheiit , Rosemaryit , Varulith and Wyllieit the "Alluaudit group" with the system number. VII / A.06 .

The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), also assigns hagendorfite to the category of “phosphates etc. without additional anions; without H 2 O “. However, this is further subdivided according to the relative size of the cations involved , so that the mineral can be found according to its composition in the sub-section “With medium-sized and large cations”, where it is named after the “Hagendorfite group” with the system no. 8.AC.10 and the other members Alluaudit, Arseniopleit, Bradaczekit , Groatit , Karyinit, Ferroalluaudit, Ferrohagendorfit, Johillerit , Maghagendorfit, Manitobait , Nickenichit , O'Danielit , Varulith and Yazganit forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns hagendorfite to the class of "phosphates, arsenates and vanadates" and there in the department of "anhydrous phosphates etc.". Here he is in the "Alluaudit-Wyllieitgruppe (Alluaudit-Untergruppe)" with the system no. 38.02.03 within the subsection " Anhydrous phosphates etc., (A + B2 +) 5 (XO4) 3 ".

Crystal structure

Hagendorfite crystallizes monoclinically in the space group I 2 / a (space group no. 15, position 3) with the lattice parameters a  = 10.93  Å ; b  = 12.59 Å; c  = 6.51 Å and β = 98.0 ° and 4 formula units per unit cell . Template: room group / 15.3

properties

Hagendorfite is very pleochroistic in thin layers, i.e. depending on the direction from which the light falls through the crystal, the mineral shows a color change from yellowish green (perpendicular to the x-axis) through blue-green to grass-green (perpendicular to the z-axis).

Education and Locations

Hagendorfite is formed in complex granite - pegmatites , where it usually occurs in association with hematite , triphylene and Wolfeit .

As a rare mineral formation, hagendorfite could only be detected in a few places, with just under 20 sites known to date. In addition to its type locality Hagendorf in the Upper Palatinate, the mineral could only be found in Germany at the Hennenkobel ( Hühnerkobel ) near Rabenstein (Zwiesel) in Lower Bavaria.

Hagendorfite is known throughout Europe from Vernéřov (German Wernersreuth) and Otov in the Czech region of Bohemia ; Lutomia ( Leutmannsdorf ) and Michałkowa ( Michelsdorf ) in the Polish region of Lower Silesia ; Mangualde in Portugal and Skrumpetorp ( Östergötland ), Norrö ( Södermanland ) and Varuträsk ( Västerbotten ) in Sweden.

Other locations are in Bolivia, Canada, Namibia, Rwanda and the United States of America (USA).

See also

literature

Web links

Commons : Hagendorfite  - collection of images, videos and audio files

Individual evidence

  1. a b c d 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.  430 .
  2. Webmineral - Hagendorfite
  3. a b Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties . 6th completely revised and supplemented edition. Weise, Munich 2014, ISBN 978-3-921656-80-8 .
  4. a b c d e Hagendorfite , In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 64.1 kB )
  5. a b c d e f g h i Mindat - Hagendorfite
  6. ^ A b Helmut Schrätze , Karl-Ludwig Weiner : Mineralogie. A textbook on a systematic basis . de Gruyter, Berlin; New York 1981, ISBN 3-11-006823-0 , pp.  612 .
  7. Mindat - Number of localities for hagendorfite
  8. Find location list for hagendorfite in the Mineralienatlas and Mindat