Manganese berelite

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Manganese berelite
General and classification
other names

Pyrrhoarsénite, Mn-Berzeliite, Manganese Oberzelite

chemical formula Ca 2+ 2 Na + Mn 2+ 2 As 5+ 3 O 12
Mineral class
(and possibly department) 		Phosphates, arsenates and vanadates
System no. to Strunz
and to Dana 		8.AC.25 ( 8th edition : 7 / A.08-40)
38.2.1.2
Crystallographic Data
Crystal system cubic
Crystal class ; symbol cubic hexakisoctahedral; 4 / m  3  2 / m
Space group Ia 3 d (No. 230)Template: room group / 230
Lattice parameters a  = 12.52 (synthetic end
link ) 12.500 (natural mixed crystal)  Å
Formula units Z  = 8
Physical Properties
Mohs hardness 4.5 - 5
Density (g / cm 3 ) natural mixed crystal: 4.21 (measured)
Cleavage not observed
colour brownish (synthetic), yellow-orange (natural mixed crystal)
Line color yellow to orange brown
transparency Please complete!
shine Resin gloss
Crystal optics
Refractive index n  = 1,777 (synthetic), 1,770 (natural mixed crystal)
Birefringence isotropic

The mineral manganese bercelite is a very rare arsenate from the garnet group and has the idealized chemical composition Ca 2+ 2 Na + Mn 2+ 2 As 5+ 3 O 12 . It crystallizes in the cubic crystal system with the structure of garnet.

Manganese berzelite occurs in the form of resinous, fine-grained masses, crusts and fissure fillings or mostly xenomorphic crystals rarely larger than one millimeter in size. The color varies with increasing manganese content from yellow to orange to brownish.

Manganese bercelite is formed during the metamorphosis of carbonate, manganese-containing sediments . The type locality is the extremely mineral-rich iron-manganese skarn deposit Långban in the municipality of Filipstad , Värmland County , Sweden .

Etymology and history

The first description of a manganese-rich, berceliite-like mineral from the Sjögruvan mine near Långban was made in 1886 by LJ Ingelström under the name Pyrrhoarsenit . After SAH Sjögren determined the manganese content in more precise chemical analyzes in 1894, which, converted into atomic proportions, corresponds to the magnesium content of berzeliite, Ingelström concluded that his pyrrhoarsenite is a manganese-rich variety of berzeliite and introduced the name manganese-berzeliite . This term has since been used in different spellings by different authors: Manganberzeliit (Hintze 1922) or Mn-Berzeliit (Landergren 1930).

Sjögren was the first to determine the previously overlooked sodium content of Manganberzelit as early as 1894. The sodium content of berzeliite was not documented until 1930, when the Austrian mineralogist Felix Machatschki determined the garnet structure of berzeliite.

In 1972 Paul B. Moore carried out another X-ray examination of the manganese arsenate of the Sjö mine described by Ingelson and was able to prove that Ingelström's pyrrhoarsenite is structurally similar to Berzeliite. He proposed that the name pyrrhoarsenite be discarded in favor of Berzeliite, but did not submit that proposal to the CNMMN. In view of the poor description of pyrrhoarsenite by Ingelström, even for the possibilities at that time, the name manganese berzelite, which was introduced later, has been retained until today.

The first syntheses were carried out in 1968 by Jun Ito from the Department of Geological Sciences at Harvard University in Cambridge (Massachusetts) . He was able to show that berzeliite and its manganese equivalent (manganese berzeliite) are completely miscible and no longer stable at temperatures above 550 ° C (1.5 kBar).

In 1995, Khorari and his co-workers were able to show with further studies on synthetic arsenate grenades that berzeliite is polymorphic and changes into the structure of alluaudite at high temperatures .

classification

The current classification of the International Mineralogical Association (IMA) counts the manganese berzeliite to the garnet upper group, where together with berzeliite , palenzonaite and shepherdite it forms the berzeliite group with 15 positive charges on the tetrahedrally coordinated lattice position.

In the outdated, partly still in use 8th edition of the mineral classification according to Strunz , the manganese berceliite 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 it belongs together with Palenzonaite, Chladniite , Fillowite , Galileiit , Johnsomervilleit , Berzeliit, Schäferit, Storneseit- (Y) and Xenophyllite formed the unnamed group VII / A.08 .

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 the manganese berceliit to the category of “phosphates etc. without additional anions; without H 2 O “. 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 sub-section C "With medium-sized and large cations", where it forms the berzeliite group 8.AC.25 with palenzonaite , berzeliite and schäferite .

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns manganese berceliite to the class of "phosphates, arsenates and vanadates" and there in the department of "anhydrous phosphates etc.". Here it is together with palenzonaite, berzeliite and schäferite in the berzeleiite group systematics of minerals according to Dana / Phosphate, Arsenate, Vanadate # 38.02.01 Berzeliite group within the subdivision "38.02 Anhydrous phosphates etc., (A + B 2+ ) 5 (XO 4 ) 3 ”.

Chemism

Manganberzeliit with the idealized composition [X] (Na + Ca 2+ 2 ) [Y] Mn 2+ 2 [Z] As 5+ 3 O 12 is the manganese -Analog of Berzeliit ( [X] (Na + Ca 2+ 2 ) [Y] Mg 2+ 2 [Z] As 5+ 3 O 12 ) as well as the arsenic analog of palenzonaite ( [X] (Na + Ca 2+ 2 ) [Y] Mn 2+ 2 [Z] V 5+ 3 O 12 ).

The following composition was determined for manganese berzelite from various locations:

  • Varenche (Italy): [X] (Ca 2+ 2.00 Na + 1.02 ) [Y] (Mn 2+ 1.57 Mg 2+ 0.44 ) [Z] (As 5+ 2.64 V 5 + 0.32 Si 4+ 0.01 ) O 12
  • Gozaisho (Japan): [X] (Ca 2+ 2.01 Na + 1.01 ) [Y] (Mn 2+ 1.82 Mg 2+ 0.17 Fe 2+ 0.01 ) [Z] (As 5 + 2.86 V 5+ 0.07 Si 4+ 0.04 ) O 12

There is a complete interchangeability of Mg and Mn on the octahedrally coordinated Y position, corresponding to the exchange reaction

  • [Y] Mn 2+ = [Y] Mg 2+

The manganese berzelite from the Varenche mine in the Aosta Valley is a mixed crystal with palenzonaite / schäferite corresponding to the exchange reaction

  • [Z] As 5+ = [Z] V 5+

Manganese berzelite from the Jakobsberg deposit near Filipstad in the province of Värmland County, Sweden, contains up to 20 mol% palenzonaite (~ 0.6 apfu V 5+ ).

Crystal structure

Manganese bercelite crystallizes with cubic symmetry in the space group Ia 3 d (space group no. 230) with 8 formula units per unit cell . The natural mixed crystal from Franklin, New Jersey, has the lattice parameter a  = 12,500  Å . The lattice parameter of synthetic, pure berzeliite is slightly larger: a  = 12.52 Å. Template: room group / 230

The structure is that of garnet . Sodium (Na + ) and calcium (Ca 2+ ) occupy the dodecahedral X position surrounded by 8 oxygen ions, manganese (Mn 2+ ) the octahedral Y position surrounded by 6 oxygen ions and the tetrahedral Z position surrounded by 4 oxygen ions is exclusive occupied with arsenic (As 5+ ).

Education and Locations

Manganese bercelite is formed during the metamorphosis of iron-manganese deposits.

The type locality is the Långban iron-manganese skarn deposit in Filipstad municipality , Värmland County , Sweden . Manganese berzelite occurs here in manganese-rich skarns together with hematite and Richterite or Hausmannite , barite , calcite and Richterite. This extremely mineral-rich manganese deposit is a type locality of over 70 other, mostly very rare minerals.

Another, similar deposit in Sweden is the Sjögruvan Mine near Grythyttan in the municipality of Hällefors , also in the province of Örebro County, Sweden. Here manganese berzelite occurs together with calcite, dolomite , hausmannite and lead .

In Italy, manganese bercelite is found in the metamorphic manganese deposits of the province of Cuneo in Piedmont , in the Aosta Valley, in Liguria and in Lombardy . On the heaps of the Miniera della Valletta in the Miara Valley in the municipality of Canosio , Piedmont, manganese berzelite was found together with braccoite , tiragalloite , gamagarite , hematite , palenzonaite, quartz , saneroite and tokyoite .

In Switzerland , manganese bercelite was found in several metamorphic manganese deposits in the Albula valley and in the Hinterrheintal in Graubünden .

Manganese berceliite occurs together with rhodochrosite , aegirine , albite and rhodonite in the amphibolite mine at the Gozaisho Mine near Iwaki in Fukushima Prefecture on the island of Honshu , Japan .

The first discovery of manganese berceliite in the USA was made by two private collectors from Warwick and Westfield . From an old collection, they acquired finds from the very mineral-rich Franklin Mine in New Jersey . Manganese berceliite occurs here in granular tunnels that run through the franklinite - willemite ore.

Other documented deposits are Mieslkopf and Unterweg im Silltal , Austria , the Palhal copper-nickel mine near Albergaria-a-Velha in Portugal , the Dzhumart iron-manganese deposit near Qaraghandy in Kazakhstan , the Kombat mine near Kombat in Namibia and the Alfredo Jahn Cave near Birongo in Miranda , Venezuela .

See also

Web links

Individual evidence

  1. ↑ a b c d e f Jun Ito: Synthesis of the Berzeliite (Ca 2 NaMg 2 As 3 O 12 ) –Manganberzelite [sic] (Ca 2 NaMn 2 As 3 O 12 ) series (arsenate garnet) . In: American Mineralogist . tape 53 , 1968, pp. 316–319 ( minsocam.org [PDF; 242 kB ; accessed on May 1, 2020]).
  2. ↑ a b c d e f g h Clifford Frondel, Jun Ito: Manganberzeliite from Franklin, New Jersey . In: American Mineralogist . tape 48 , 1963, pp. 663–664 ( minsocam.org [PDF; 133 kB ; accessed on May 1, 2020]).
  3. ↑ a b c Manganese bercelite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 (English, handbookofmineralogy.org [PDF; 63  kB ; accessed on May 1, 2020]).
  4. ↑ a b c d M. Nagashima, T. Armbruster: Palenzonaite, berzeliite, and manganberzeliite: (As 5+ , V 5+ , Si 4+ ) O 4 tetrahedra in garnet structures . In: Mineralogical Magazine . tape 76 , 2012, p. 1081-1097 ( rruff.info [PDF; 380 kB ; accessed on May 1, 2020]).
  5. ↑ a b c Photos of Manganberzeliit. In: mindat.org. Hudson Institute of Mineralogy, accessed May 1, 2020 .
  6. ↑ a b c d e f Find location list for Berzeliite in the Mineralienatlas and in Mindat
  7. ↑ a b c d Edward S. Grew, Andrew J. Locock, Stuart J. Mills, Irina O. Galuskina, Evgeny V. Galuskin and Ulf Hålenius: IMA Report - Nomenclature of the garnet supergroup . In: American Mineralogist . tape 98 , 2013, p. 785-811 ( cnmnc.main.jp [PDF; 2.0 MB ; accessed on May 1, 2020]).
  8. ^ Felix Machatschki: IX. Berzeliite, an arsenate of the formula and structure type garnet (X3 Y2 Z3 O12) . In: Journal of Crystallography - Crystalline Materials . tape 73 , 1930, pp. 123-140 , doi : 10.1524 / zkri.1930.73.1.123 .
  9. ^ Felix Machatschki: XXIV. Shorter original communications and notes: About Berzeliit . In: Journal of Crystallography - Crystalline Materials . tape 74 , 1930, pp. 230-236 , doi : 10.1524 / zkri.1930.74.1.230 .
  10. ^ Paul B. Moore: Contributions to the Mineralogy of Sweden III. On Igelström's Manganese Arsenates and Antimonates from the Sjö Mine, Grythyttan, Örebro County, Sweden . In: Geologiska Föreningens i Stockholm Förhandlingar . tape 94 , 1972, pp. 423-434 , doi : 10.1080 / 11035897209455408 .
  11. ↑ S. Khorari, A. Rulmont, R. Cahay, P. Tarte: Structure of the Complex Arsenates NaCa 2 M 2+ 2 (AsO 4 ) 3 (M 2+ = Mg, Ni, Co): First Experimental Evidence of a Garnet-Alluaudite Reversible Polymorphism . In: Journal of Solid State Chemistry . tape 118 , 1995, pp. 267-273 , doi : 10.1006 / jssc.1995.1343 .
  12. ^ Dan Holtstam: W and V mineralization in Långban-type Fe-Mn deposits: Epigenetic or syngenetic? In: GFF . tape 123 , 2001, p. 29-33 , doi : 10.1080 / 1103589010123102 .
  13. ↑ Fernando Cámara, Erica Bittarello, Marco E. Ciriotti, Fabrizio Nestola, Francesco Radica, Marco Marchesini: As-bearing new mineral species from Valletta mine, Maira Valley, Piedmont, Italy: II. Braccoite, NaMn 2+ 5 [Si 5 AsO 17 (OH)] (OH), description and crystal structure . In: Mineralogical Magazine . tape 79 , 2015, p. 171–189 ( iris.unito.it [PDF; 7.0 MB ; accessed on May 1, 2020]).
  14. ↑ Satoshi Matsubara: Manganberzeliite from the Gozaisho Mine, Fukushima Prefecture, Japan . In: Kobutsugaku Zasshi . tape 12 , 1975, p. 238–253 (Japanese, jstage.jst.go.jp [PDF; 5.2 MB ; accessed on May 1, 2020]).