Ferrilotharmeyerite

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Ferrilotharmeyerite
Silver-Adamite-Ferrilotharmeyerite-163982.jpg
Yellow ferrilotharmeyerite accompanied by green cuproadamine and solid silver from the Tsumeb mine near Tsumeb, Otjikoto region, Namibia (size: 4.1 cm × 2.6 cm × 1.3 cm)
General and classification
other names

IMA 1986-024

chemical formula
  • Ca (Fe 3+ , Zn) 2 (AsO 4 ) 2 (OH, H 2 O) 2
  • Ca (Fe 3+ , Zn, Cu) 2 (AsO 4 ) 2 (OH, H 2 O) 2
  • Ca (Fe 3+ , Zn) 2 [(OH, H 2 O) 2 | (AsO 4 ) 2 ]
  • Ca (Zn, Cu) (Fe 3+ , Zn) (AsO 3 OH) 2 (OH) 3
Mineral class
(and possibly department) 		Phosphates, arsenates, vanadates
System no. to Strunz
and to Dana 		8.CG.15 ( 8th edition : VII / C.31)
01/37/06/02
Similar minerals Tsumcorite, Gartrellite, Beaverite (Cu)
Crystallographic Data
Crystal system monoclinic
Crystal class ; symbol monoclinic prismatic; 2 / m
Space group C 2 / m (No. 12)Template: room group / 12
Lattice parameters a  = 8.991  Å ; b  = 6.218 Å; c  = 7.398 Å
β  = 115.33 °
Formula units Z  = 2
Physical Properties
Mohs hardness ≈ 3
Density (g / cm 3 ) 4.25 (measured); 4.25-4.32 (calculated)
Cleavage good after {001}
Break ; Tenacity uneven; brittle
colour yellow to brownish yellow, reddish brown to brown
Line color pale yellow
transparency translucent
shine Greasy shine

Ferrilotharmeyerite is a very rarely occurring mineral from the mineral class of " phosphates , arsenates and vanadates ". It crystallizes in the monoclinic crystal system with the chemical composition Ca (Fe 3+ , Zn) 2 (AsO 4 ) 2 (OH, H 2 O) and is therefore chemically a water-containing calcium - iron - zinc - arsenate with a variable proportion of additional Hydroxide ions .

Ferriotharmeyerite develops tabular, wedge-shaped or diamond-shaped crystals up to 0.6 mm in size at its type locality , which come together to form sub-parallel aggregates with a maximum diameter of 3 mm. Adhesions with beudantite are typical ; other companions are chenevixite , cuproadamin , "silver amalgam ", chudobait and gaitit . The type locality of the mineral is the Tsumeb Mine near Tsumeb , Otjikoto Region , Namibia .

Etymology and history

Julius Lothar von Meyer - namesake for Lotharmeyerite and the related Ferrilotharmeyerite

A step recovered in 1983 by John Innes, chief mineralogist of the Tsumeb Corporation, on the 32nd level in the W40 mining of the Tsumeb Mine in Tsumeb, Namibia, which had entered the National Mineral Collection of the Geological Survey of Canada, was found in the mid-1980s identified a phase that could not be assigned to any known mineral. After most of the extensive investigations required for characterization as a new mineral had already been carried out, a second stage with the same phase, also from the Tsumeb deposit, appeared in the collection of the Museum of Victoria, Melbourne, Australia. After additional investigations were carried out on this material, the new mineral was submitted to the International Mineralogical Association (IMA), which recognized it in 1986. In 1992 the mineral was discovered by an international team of scientists led by the Canadian mineralogist Harold Gary Ansell and Andrew C. Roberts, Valerie E. Ansell, Pete J. Dunn , William D. Birch and Joël D. Grice in the Canadian scientific magazine "The Canadian Mineralogist" described as ferrilotharmeyerite. The authors named the mineral because of its relationship to Lotharmeyerite and the dominance of trivalent iron Fe 3+ on the Me (2) position.

The material originally used to characterize the mineral species ferrilotharmeyerite from the "National Mineral Collection" of the Geological Survey of Canada in Ottawa (catalog number NMC 6457), on which the majority of the analyzes for recognition by the IMA were carried out, later turned out to be lotharmeyerite. The material from the Tsumeb mine used by Werner Krause and co-workers to obtain new data also only represents Lotharmeyerite. With this, all of the crystal-optical data ascribed to Ferrilotharmeyerite have actually been determined on Lotharmeyerite crystals.

The type material for ferrilotharmeyerite (holotype) is kept under catalog number 163579 in the collection of the Smithsonian Institution's National Museum of Natural History , Washington, DC , USA . Other type material used for characterization as a mineral is in the collection of the Museum of Victoria (now the Melbourne Museum in Melbourne , Australia , catalog number M3809).

classification

The current classification of the International Mineralogical Association (IMA) counts ferrilotharmeyerite to the tsumcorite group with the general formula Me (1) Me (2) 2 (XO 4 ) 2 (OH, H 2 O) 2 , in which Me (1), Me (2) and X different positions in the structure of the minerals of the tsumcorite group with Me (1) = Pb 2+ , Ca 2+ , Na + , K + and Bi 3+ ; Me (2) = Fe 3+ , Mn 3+ , Cu 2+ , Zn 2+ , Co 2+ , Ni 2+ , Mg 2+ and Al 3+ and X = As 5+ , P 5+ , V 5+ and represent S 6+ . To Tsumcoritgruppe include not only Ferrilotharmeyerit still Cabalzarit , Cobaltlotharmeyerit , Cobalttsumcorit , Gartrellit , Helmutwinklerit , Kaliochalcit , Krettnichit , Lotharmeyerit , Lukrahnit , Manganlotharmeyerit , Mawbyit , Mounanait , Natrochalcit , Nickellotharmeyerit , Nickelschneebergit , Nickeltsumcorit , Phosphogartrellit , Rappoldit , Schneebergit , Thometzekit , Tsumcorit , Yancowinnait and Zinc Gartrellite . Ferrilotharmeyerite together with cabalzarite ( Me (2) = Mg), cobaltlotharmeyerite (Co), lotharmeyerite (Zn), manganese solderarmyerite (Mn 3+ ) and nickellotharmeyerite (Ni) form the "Lotharmeyerite subgroup" named after Lotharmeyerite.

In the now outdated, but still in use 8th edition of the mineral classification according to Strunz , the ferrilotharmeyerite belonged to the mineral class of "phosphates, arsenates and vanadates" and there to the division of "water-containing phosphates without foreign anions ", where it was found together with cabalzarite, cobalt solder archerite, cobalt sumcorite , Gartrellite, Helmutwinklerit, Krettnichit, Lotharmeyerit, Lukrahnit, Manganlotharmeyerit, Mawbyit, Mounanait, Nickellotharmeyerit, Nickelschneebergit, Phosphogartrellite, Rappoldit, Schneebergit, Thometzekit, Tsumcorit and zinc gartrellite-group "Tsumcorit-Nr." VII / C.31 formed.

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 ferrilotharmeyerite to the category of “phosphates etc. without additional anions; with H 2 O “. However, this is further subdivided according to the relative size of the cations involved and the molar ratio of phosphate, arsenate or vanadate complex to the water of crystallization content , so that the mineral can be classified according to its composition in the subsection “With large and medium-sized cations; RO 4  : H 2 O = 1: 1 "is to be found, where together with Cabalzarite, Cobaltlotharmeyerite, Cobalttsumcorit, Krettnichit, Lotharmeyerit, Manganlotharmeyerit, Mawbyit, Mounanait, Nickellotharmeyerit, Nickelschneebergit, Schneebergite", Thometzekit the "Tsumcorite and Tsumcorite System no. 8.CG.15 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns ferrilotharmeyerite to the class of "phosphates, arsenates and vanadates" and there to the department of "phosphate minerals". Here it is together with cobalt solder armorite, solder armorite and nickellotharmeyerite in the " Lotharmeyerite series " with the system no. 37.01.06 to be found in the subsection of "Anhydrous acidic phosphates etc., with various formulas".

Chemism

Microprobe analyzes on ferrilotharmeyerite from the Tsumeb mine showed mean values ​​of 10.86% CaO; 5.75% CuO; 13.94% ZnO; 2.13% PbO; 13.96% Fe 2 O 3 ; 0.13% Al 2 O 3 ; 48.66% As 2 O 3 and 5.85% H 2 O, from which the empirical formula (Ca 0.92 Pb 0.05 ) Σ = 0.97 (Fe 0.87 Zn 0.81 Cu 0.34 Al 0.01 ) Σ = 2.03 (AsO 4 ) 2 (OH, H 2 O) 2 , which results in Ca (Fe 3+ , Zn, Cu) 2 (AsO 4 ) 2 (OH, H 2 O ) 2 can be idealized.

Another five microprobe analyzes on ferrilotharmeyerite from the Pucherschacht in Schneeberg yielded mean values ​​of 10.43% CaO; 4.60% Bi 2 O 3 ; 11.13% NiO; 4.27% CoO; 0.09% CuO; 1.88% ZnO; 0.27% PbO; 15.18% Fe 2 O 3 ; 0.10% Al 2 O 3 ; 48.66% As 2 O 3 ; 0.28% P 2 O 5 ; 0.09% V 2 O 5 ; <0.05% SO 3 and 5.26% H 2 O. On the basis of ten oxygen atoms , the empirical formula (Ca 0.91 Bi 0.10 ) Σ = 1.01 (Fe 3+ 0, 93 Ni 0.73 Co 0.28 Zn 0.11 Al 0.01 ) Σ = 2.06 [(PO 4 ) 0.02 (AsO 4 ) 1.94 ] Σ = 1.96 [(OH) 1, 30 (H 2 O) 0.86 ] Σ = 2.16 , which can be idealized to Ca (Fe 3+ , Ni, Co, Zn) 2 (AsO 4 ) 2 (OH, H 2 O) 2 .

Ferrilotharmeyerite is the Fe 3+ -dominant analogue of the Zn-dominated Lotharmeyerite, with which it forms a possibly complete mixed crystal row . It is also the corresponding analogue to the Mg-dominated Cabalzarite, to the Mn 3+ -dominated manganese solder armyerite, to the Co-dominated cobalt solder armyerite and to the Ni-dominated nickellotharmeyerite, whereby mixed crystal rows are obviously also possible with cobalt solder armyerite and nickellotharmeyerite.

Crystal structure

Ferrilotharmeyerite crystallizes in the monoclinic crystal system in the space group C 2 / m (space group no. 12) with the lattice parameters a  = 8.991  Å ; b  = 6.218 Å; c  = 7.398 Å and β = 115.33 ° as well as two formula units per unit cell . Template: room group / 12

The crystal structure of the Ferrilotharmeyerits is made of stretched by [001], rutile -like chains of Fe 3+ O 6 - octahedra (Symmetry 1 formed) obtained by As O 4 - tetrahedron (symmetry 2 / m ) and hydrogen bonds are connected and [ M 2 ( X O 4 ) 2 (OH, H 2 O) 2 ] layers parallel to form (001). These layers are linked by the larger Me (1) cations (Ca 2+ , symmetry 2 / m ) and other hydrogen bonds.

Ferrilotharmeyerite is isotypic (isostructural) to the monoclinic representatives of the tsumcorite group such as tsumcorite and natrochalcite and the other above-mentioned representatives of the lotharmeyerite subgroup.

properties

morphology

At its type locality, ferrilotharmeyerite develops subparallel fused aggregates with a maximum diameter of 3 mm, which consist of tabular, wedge-shaped or diamond-shaped crystals up to 0.6 mm in size. Ferrilotharmeyerite from Bou Azzer forms tiny strips and needles as well as earthy, finely crystalline crusts. Ferrilotharmeyerite from the "Clara pit" in the Black Forest was found in the form of inconspicuous thin crystal crusts, while ferrilotharmeyerite from Lavrion forms tiny, scaly crystals. From ferrilotharmeyerite pseudomorphoses after tennantite crystals have been described.

physical and chemical properties

The crystals of Ferrilotharmeyerite are yellow to brownish yellow or reddish brown to brown, their streak color , however, is pale yellow. The surfaces of the translucent crystals have a greasy sheen .

Ferrilotharmeyerite has good cleavage properties in parallel {001}, but because of its brittleness it breaks like amblygonite , with the fracture surfaces being uneven. With a Mohs hardness of ≈ 3, the mineral is one of the medium-hard minerals and, like the reference mineral calcite, can be scratched with a copper coin. The measured density for ferrilotharmeyerite is 4.25 g / cm³, the calculated density 4.25-4.32 g / cm³. The mineral is neither in the long term nor in the short wavelength UV light , a fluorescent .

There is no information on the chemical behavior, especially towards acids.

Education and Locations

Green cuproadamine crystals with ferrilotharmeyerite inclusions next to light yellow beaverite (Cu) from the Tsumeb Mine, Namibia (step size: 3.4 cm × 2.9 cm × 1.3 cm)

Ferrilotharmeyerit is a typical secondary mineral , which is located in the oxidation zone of arsenic-rich polymetallic non-ferrous metal - deposits formed.

At the type locality "Tsumeb Mine", the mineral was found on a level of solid tennantite and calcite. At this level there is a 7 × 7 cm crust of dark brown, tabular beudantite crystals up to 1 mm in size, on which there are tiny ferrilotharmyerite crystals, some of which have grown together with the beudantite. Species found in 1993 on the 44th level in Tsumeb show tabular brown ferrilotharmyerite crystals up to 1 mm in size, which sit on a crystalline crust of apple-green chenevixite and are accompanied by crystals of a silver amalgam. Furthermore, all cuproadamine crystals found on the 43rd floor in Tsumeb are accompanied by ferrilotharmeyerite - either in the form of a microcrystalline yellow crust under the cuproadamine, as yellow inclusions in cuproadamine crystals or as clear, brown crystals together with cuproadamine. The original type of ferrilotharmeyerite, which was found by John Innes in the W40 mine on the 32nd floor in Tsumeb, has proven to be Lotharmeyerite

Paragenesis minerals in the “Tsumeb Mine” are beudantite , chenevixite , cuproadamine , “silver amalgam” and chudobaite as well as gaitit . In the "Clara mine" the mineral occurs together with barite , quartz and zinc-bearing olivite , while ferrilotharmeyerite was found in Bou Azzer together with talmessite , lollingite , chalcopyrite , konichalcite , cobaltaustinite and spherocobaltite . In Lavrion, ferrilotharmeyerite is accompanied by nickellotharmeyerite.

As a very rare mineral formation, ferrilotharmeyerite could only be described in seven sites so far (as of 2018). The type locality is the "Tsumeb Mine" near Tsumeb, Otjikoto region, Namibia. The mineral was found here on various deeper levels in the second oxidation zone, including the so-called “third oxidation zone”.

The world's second location was Schneeberg in the Erzgebirge , Saxony , Germany . Ferrilotharmeyerite could be recovered here in the heaps of the “Pucherschacht” in the “Wolfgang Maaßen” mine field and in the “Am Roten Berg” mine field.

In Germany , ferrilotharmeyerite is only known from the Clara mine in the Rankach valley near Oberwolfach , Black Forest , Baden-Württemberg .

Another location is the mining area of ​​Bou Azzer near Taznakht (Tazenakht), Ouarzazate province in the Drâa-Tafilalet region in southern Morocco . Here cobalt-rich ferrilotharmeyerite was first found on "Gang No. 52 ”in Aït Ahmane in tiny red-brown strips together with talmessite in the brecciated lollingite. Another find comes from the Aghbar opencast mine. Brown needles made of cobalt-rich ferrilotharmeyerite were found here in cavities in the decomposed chalcopyrite, where they are encrusted with dark green conichalcite and cobalt austinite and accompanied by spherocobaltite rhombohedra.

Finally, ferrilotharmeyerite has also been found in the mine “Km 3” west of Lavrion near Agios Konstantinos (Kamariza) not far from Plaka, Lavrion mining district , Attica region , Greece together with and next to nickellotharmeyerite.

There are therefore no known occurrences of ferrilotharmeyerite in Austria or Switzerland .

use

Due to its rarity, ferrilotharmeyerite is only of interest to the mineral collector.

See also

literature

  • Harold Gary Ansell, Andrew C. Roberts, Pete J. Dunn, William D. Birch, Valerie E. Ansell, Joël D. Grice: Ferrilotharmeyerite, a new Ca-Zn-Fe 3+ hydroxyl arsenate from Tsumeb, Namibia . In: The Canadian Mineralogist . tape 30 , 1992, pp. 225–227 ( rruff.info [PDF; 275 kB ; accessed on May 15, 2018]).
  • Ferrilotharmeyerite . 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; 66 kB ; accessed on May 15, 2018]). (Attention! - the data contain numerous values ​​for "Ferrilotharmeyerite" from the "Tsumeb Mine", which is actually "Lotharmeyerite")

Web links

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

Individual evidence

  1. ↑ a b c d Werner Krause, Klaus Belendorff, Heinz-Jürgen Bernhardt, Catherine McCammon, Herta Effenberger, Werner Mikenda: Crystal chemistry of the tsumcorite-group minerals. New data on ferrilotharmeyerite, tsumcorite, thometzekite, mounanaite, helmutwinklerite, and a redefinition of gartrellite . In: European Journal of Mineralogy . tape 10 , no. 2 , 1998, p. 179-206 , doi : 10.1127 / ejm / 10/2/0179 .
  2. ↑ a b c d Ferrilotharmeyerite . 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; 66  kB ; accessed on May 15, 2018]).
  3. ^ Hugo Strunz , Ernest H. Nickel : Strunz Mineralogical Tables . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p.  485 .
  4. ↑ a b c d e f g h i j k l m n o p q r s t u v w x Harold Gary Ansell, Andrew C. Roberts, Pete J. Dunn, William D. Birch, Valerie E. Ansell, Joël D. Grice: Ferrilotharmeyerite, a new Ca-Zn-Fe 3+ hydroxyl arsenate from Tsumeb, Namibia . In: The Canadian Mineralogist . tape 30 , 1992, pp. 225–227 ( rruff.info [PDF; 275 kB ; accessed on May 15, 2018]).
  5. ↑ Tsumeb.com - Ferrilotharmeyerite
  6. ↑ a b c d e f Werner Krause, Herta Effenberger, Heinz-Jürgen Bernhardt, Mirko Martin: Cobalttsumcorite and nickellotharmeyerite, two new minerals from Schneeberg, Germany: description and crysral structure . In: New yearbook for mineralogy, monthly books . tape 2001 , no. 12 , 2001, p. 558-576 .
  7. ↑ a b c d Georges Favreau, Jacques Emile Dietrich: The minerals of Bou Azzer . In: Lapis . tape 31 , no. 7–8 , 2006, pp. 54 .
  8. ↑ a b Werner Krause, Heinz Jürgen Bernhardt, Herta Effenberger, Thomas Witzke: Schneebergite and nickelschneebergite from Schneeberg, Saxony, Germany: the first bi-bearing members of the tsumcorite group . In: European Journal of Mineralogy . tape 14 , 2002, p. 115-126 , doi : 10.1127 / 0935-1221 / 02 / 0014-0115 .
  9. ↑ a b c d Joël Brugger, Sergey V. Krivovichev, Uwe Kolitsch, Nicolas Meisser, Michael Andrut, Stefan Ansermet, Peter C. Burns: Description and crystal structure of manganlotharmeyerite, Ca (Mn 3+ , ◻, Mg) 2 {AsO 4 , [AsO 2 (OH) 2 ]} 2 (OH, H 2 O) 2 from the Starlera Mn deposit, Swiss Alps, and a redefinition of lotharmeyerite . In: The Canadian Mineralogist . tape 40 , no. 4 , 2002, p. 1597–1608 , doi : 10.2113 / gscanmin.40.6.1597 ( rruff.info [PDF; 1.1 MB ; accessed on February 20, 2018]).
  10. ↑ a b Catalog of Type Mineral Specimens - F. (PDF 73 kB) In: docs.wixstatic.com. Commission on Museums (IMA), December 12, 2018, accessed August 29, 2019 .
  11. ^ Yongbo W. Yang, Stanley H. Evans, Robert T. Downs, Hexiong Yang: Lotharmeyerite, Ca (Zn, Mn) 2 (AsO 4 ) 2 (H 2 O, OH) 2 . In: Acta Crystallographica . E68, 2012, p. i9 – i10 , doi : 10.1107 / S1600536811054286 ( rruff.info [PDF; 727 kB ; accessed on February 20, 2018]).
  12. ↑ Mindat - Ferrilotharmeyerite
  13. ↑ a b c Uwe Kolitsch, Branko Rieck, Franz Brandstätter, Fritz Schreiber, Karl Heinz Fabritz, Günter Blaß, Joachim Gröbner: New finds from the old mining and the slag from Lavrion (I) . In: Mineral World . tape 25 , no. 1 , 2014, p. 60-75 .
  14. ↑ a b c d e Georg Gebhard: Tsumeb . 1st edition. GG Publishing, Grossenseifen 1999, ISBN 3-925322-03-5 , pp. 256-257 .
  15. ↑ Bill Pinch - Ferrilotharmeyerite
  16. ↑ a b Uwe Kolitsch, Joachim Gröbner, Günter Blaß, Hans-Werner Graf, Allan Pring: New finds from the Clara pit in the central Black Forest (II) . In: Lapis . tape 30 , no. 9 , 2005, p. 35-39 .
  17. ↑ Mindat - Number of localities for ferrilotharmeyerite
  18. ↑ a b List of locations for ferrilotharmeyerite in the Mineralienatlas and Mindat