Nickellotharmeyerite

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Nickellotharmeyerite
Nickellotharmeyerite.jpg
Yellow-brown nickellotharmeyerite crystal aggregates in a cavity in the quartz from the dump of the Pucherschacht near Schneeberg in the Saxon Ore Mountains
General and classification
other names

IMA 1999-008

chemical formula Ca (Ni, Fe) 2 (AsO 4 ) 2 (H 2 O, OH) 2
Mineral class
(and possibly department) 		Phosphates, arsenates, vanadates
System no. to Strunz
and to Dana 		8.CG.15 ( 8th edition : VII / C.31)
01/37/06/04
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  = 9.005  Å ; b  = 6.205 Å; c  = 7.411 Å
β  = 115.31 °
Formula units Z  = 2
Frequent crystal faces { 1 01}
Physical Properties
Mohs hardness 4.5, VHN 25  = 500 ± 50 kg / mm 2
Density (g / cm 3 ) 4.45 (calculated)
Cleavage no
Break ; Tenacity clamshell; brittle
colour brown to yellow
Line color light brown to yellow
transparency transparent
shine Semi-diamond luster, resin luster
Crystal optics
Refractive indices n α  = 1.80
n β  = 1.81
n γ  = 1.87
Birefringence δ = 0.070
Optical character biaxial positive
Axis angle 2V = 40 ° (measured)
Pleochroism strong from X = yellow to Y = brown to Z = pale yellow
Other properties
Chemical behavior slowly soluble in warm, dilute hydrochloric acid without effervescence

Nickellotharmeyerit 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 (Ni, Fe) 2 (AsO 4 ) 2 (H 2 O, OH) 2 and is therefore chemically a water-containing calcium - nickel - iron - arsenate with a variable proportion of additional hydroxide ions .

Nickellotharmeyerite develops at its type locality in cavities of decomposed nickel / cobalt arsenides in coarse-grained quartz crystals with a maximum size of 50 µm, which come together to form tiny aggregates with a maximum diameter of 0.5 mm and microcrystalline crusts. Only one step had “large” crystals up to 0.1 mm long. The type locality of the mineral is the dump of the Pucherschacht in the mine field "Wolfgang Maaßen", Schneeberg in the Saxon Erzgebirgskreis , Erzgebirge , where bismuth ores were mined in the second half of the 19th century . The mine field with the dump complex of “Pucherschacht” and “Friedefürst”, in which bismuth ores had been heaped as uselessly since 1868, was named “New California” because of the unexpectedly high profit made in a short time.

Etymology and history

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

At the end of the 1990s, the Schneeberg collector Fritz Schlegel discovered cavities in the coarse-grained quartz on the dump of the Pucherschacht in Schneeberg, which, in addition to powdery “limonite”, were filled with a visually unidentifiable mineral. Initial investigations showed that this mineral is a new member of the tsumcorite group, which is very similar to the cobalt solder armyerite already described at that time and the minerals snow mountainite and nickel snow mountainite, which were still being processed at that time. After further extensive research, the new phase was presented to the International Mineralogical Association (IMA), which recognized it as a new mineral in 1999. In 2001 the mineral was described by an international team of scientists led by the German scientist Werner Krause as well as Herta Effenberger, Heinz-Jürgen Bernhardt and Mirko Martin in the German science magazine “New Yearbook for Mineralogy, monthly books” as nickellotharmeyerite. The authors named the mineral because of its kinship with Lotharmeyerite and the dominance of nickel on the Me (2) position.

The type material for nickellotharmeyerite is stored under the catalog numbers 18329 Sa (MMG) (holotype) and 18328 Sa (MMG) (cotype) at the "Tresor" location in the Museum of Mineralogy and Geology Dresden within the Senckenberg Natural History Collections Dresden in Dresden , Germany.

classification

The current classification of the International Mineralogical Association (IMA) counts nickellotharmeyerite 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 Nickellotharmeyerit still Cabalzarit , Cobaltlotharmeyerit , Cobalttsumcorit , Ferrilotharmeyerit , Gartrellit , Helmutwinklerit , Kaliochalcit , Krettnichit , Lotharmeyerit , Lukrahnit , Manganlotharmeyerit , Mawbyit , Mounanait , Natrochalcit , Nickelschneebergit , Nickeltsumcorit , Phosphogartrellit , Rappoldit , Schneebergit , Thometzekit , Tsumcorit , Yancowinnait and Zinc Gartrellite . Together with Lotharmeyerite ( Me (2) = Zn), Cabalzarite (Mg), Cobalt Solotharmeyerite ( Co), Ferrilotharmeyerite (Fe 3+ ) and Manganese Solotharmeyerite (Mn) the "Lotharmeyerite subgroup".

In the now outdated, but still in use 8th edition of the mineral classification according to Strunz , the nickellotharmeyerite belonged to the mineral class of "phosphates, arsenates and vanadates" and there to the department of "water-containing phosphates without foreign anions ", where it belongs together with cabalzarite, cobaltlotharmeyerite, cobalt sumcorite , Ferrilotharmeyerit, Gartrellite, Helmutwinklerit, Krettnichit, Lotharmeyerit, Lukrahnit, Manganlotharmeyerit, Mawbyit, Mounanait, Nickelschneebergit, Phosphogartrellite, Rappoldit, Schneebergit, Thometzekit, Tsumcorit and Zincgartrellit-Nr. Gartrellit-group with the system "Tsumcorit" 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 nickel-thymeyerite 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, Ferrilotharmeyerit, Krettnichit, Lotharmeyerit, Manganlotharmeyerit, Mawbyit, Mounanait, Nickelschneebergit, Schneebergite", Thometzekit the "Tsumcorite group 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 nickel solder armyerite to the class of "phosphates, arsenates and vanadates" and there to the department of "phosphate minerals". Here it is together with Lotharmeyerite, Ferrilotharmeyerite and Cobaltlotharmeyerite 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

Eleven microprobe analyzes on nickellotharmeyerite showed mean values ​​of 9.29% CaO; 12.86% NiO; 3.83% CoO; 0.11% CuO; 0.62% ZnO; 0.90% PbO; 12.88% Fe 2 O 3 ; 8.56% Bi 2 O 3 ; 0.23% P 2 O 5 ; 45.32% As 2 O 5 ; 0.12% SO 3 and 5.35% H 2 O (calculated) and smaller amounts (<0.05% by weight) of Al 2 O 3 and V 2 O 5 . On the basis of ten oxygen atoms , the empirical formula (Ca 0.83 , Bi 0.18 Pb 0.02 ) Σ = 1.03 (Ni 0.86 Fe 3+ 0.81 Co 0.26 Zn 0 , 04 ) Σ = 1.97 [(AsO 4 ) 1.98 (PO 4 ) 0.02 ] Σ = 2.00 [(OH) 1.01 (H 2 O) 0.98 ] Σ = 1.99 which was idealized to Ca (Ni, Fe 3+ ) (AsO 4 ) 2 (H 2 O, OH) 2 .

Nickellotharmyerite crystals found in Aït Ahmane, Bou Azzer, Morocco have significant levels of manganese.

Solid solution formation on the Me (2) position involving Co, Fe 3+ and Ni is widespread in the crystals . The substitution of Ca by Bi 3+ is of particular interest , the measured contents being between 6 and 12% by weight of Bi 2 O 3 . Overall, the mixed crystal formation on the Me (2) position is accompanied by a Ca / Bi substitution on the Me (1) position. The relevant heterovalent exchange mechanism is [Ca 2+ Me (2) 3+ ] 5+ ↔ [Bi 3+ Me (2) 2+ ] 5+ . In this way, there are different mixed crystals between nickel-sulpharmyerite, cobalt-solderarmyerite, nickel schneebergite and snow mountainite - often even at the same level in z. T. in the immediate vicinity. The common occurrence of cobalt and nickel in the corresponding mixed crystals is typical for Schneeberg - pure cobalt or nickel members, on the other hand, are unknown. Furthermore, due to the coupled substitution [ Me (1) 2+ Me (2) 3+ ] ↔ [ Me (1) 3+ Me (2) 2+ ], an (OH): H 2 O) ratio of almost 1: 1 possible.

Nickellotharmeyerite is the Ni-dominant analogue to the Zn-dominated Lotharmeyerite. It is also the corresponding analogue to the Mg-dominated Cabalzarite, to the Fe 3+ -dominated ferrilotharmeyerite, to the Mn 3+ -dominated manganese solderarmyerite and to the co-dominated cobalt solderarmyerite. Nickel solder armyerite is also the Ca-dominated analogue of the Bi-dominated nickel snow mountainite, with which it forms a complete series of mixed crystals . All in all, unlimited mixed crystal formation is possible between nickellotharmeyerite and cobalt solderarmyerite on the one hand and nickel snow mountainite and snow mountainite on the other. Finally, nickellotharmeyerite also forms a mixed crystal row with nickel sumcorite, the nickel-dominant analog of the Zn-dominated tsumcorite.

Crystal structure

Nickellotharmeyerite crystallizes in the monoclinic crystal system in the space group C 2 / m (space group no. 12) with the lattice parameters a  = 9.005  Å ; b  = 6.205 Å; c  = 7.411 Å and β = 115.31 ° as well as two formula units per unit cell . Template: room group / 12

The crystal structure of Nickellotharmeyerite is identical to the structure of the other representatives of the tsumcorite group. The Me (2) Φ 6 - octahedra (Φ: O 2− , OH - , H 2 O) have common edges and are arranged as chains stretched in the direction of the b-axis [010]. These chains are shared by corners with AsO 4 - tetrahedra linked to each other, thereby forming layers having the composition Me (2) (AsO 4 ) (OH, H 2 O), which are arranged in parallel (001). The topology of this layer is identical to that in natrochalcite, NaCu 2 (SO 4 ) 2 (H 3 O 2 ). The Ca 2+ cations are located between the layers and ensure the connection between the layers in the direction of the a-axis [100].

Nickellotharmeyerite 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

Nickellotharmeyerit developed in the material from "Pucherschacht" according to { 1 01} tabular and from the b-axis [010] elongated crystals with a maximum size of <0.1 mm, which meet in semi-millimeter-sized aggregates. They are mostly located in the coarse-grained cell quartz in angular hollow forms of dissolved Ni / Co arsenides. Only the surface shape { 1 01} has been identified on the tiny crystals .

In the 1990s in cavities in the Talmessite on "Corridor No. 52 ”in Aït Ahmane, Bou Azzer, Morocco, nickellotharmyerite crystals form spherical aggregates with a maximum diameter of 0.1 mm. This nickellotharmeyerite has clear Mn contents and shows sharp, beudantite-like crystals when magnified. Nickellotharmyerite from Lavrion, Greece, forms crusts of tiny, flaky crystals or earthy coatings.

physical and chemical properties

The crystals of nickel solder armyerite are brown to yellow. Its color depends to a certain extent on the amount of Fe 3+ built into the crystal lattice , which correlates with the bismuth content. Bismuth-free nickellotharmeyerite is brown to red-brown, the color is lightened to brown-yellow to brown with increasing bismuth and decreasing iron content. Almost cobalt-free nickellotharmeyerite from Lavrion is yellowish green. In contrast, the color of the streak of the nickel thymeyerite crystals is always light brown.

The surfaces of the transparent crystals have a semi-diamond-like sheen , which agrees well with the values ​​for light refraction . Very high values ​​for the refraction of light (n α  = 1.80; n β  = 1.81; n γ  = 1.87) and for the birefringence (δ = 0.070) were identified on the crystals of nickel thymeyerite . The higher values ​​for the light refraction result in the semi-diamond luster of nickelotharmeyerite compared to cobalt solderarmeyerite (glass luster). Under the microscope , the mineral shows a strong pleochroism from X = yellow to Y = brown to Z = pale yellow in transmitted light .

Nickellotharmeyerite has no cleavage . Due to its brittleness , however , it breaks in a similar way to quartz , with the fracture surfaces being shell-shaped. With a Mohs hardness of 4.5, the mineral is one of the medium-hard minerals, so it stands between the reference minerals fluorite (hardness 4) and apatite (hardness 5) and, like these, can be easily scratched with a pocket knife more (fluorite) or less (apatite) . The Vickers hardness VHN 25 was determined to be 500 ± 50 kg / mm 2 . The calculated density for nickellotharmeyerite is 4.45 g / cm³. The mineral does not fluoresce in long or short-wave UV light .

Nickellotharmeyerite is only slowly soluble in warm, dilute hydrochloric acid , HCl, without effervescence.

Education and Locations

Nickellotharmeyerit is a typical secondary mineral , which, as the most representative of Tsumcoritgruppe in which oxidation zone of arsenic-rich polymetallic non-ferrous metal - deposits formed. Decomposed anhydrite provided the calcium necessary for mineral formation, bismuth comes from the weathering of native bismuth, Co, Fe 3+ and Ni were probably made available during the dissolution of minerals of the skutterudite-nickel-cutterudite mixed crystal series, to which the hollow shapes described go back.

The type locality of the Nickellotharmeyerite is the "Pucherschacht" in the Schneeberger mine field "Wolfgang Maaßen", Ore Mountains , Saxony , Germany . Paragenesis minerals are Ni / Co-containing ferrilotharmeyerite, mawbyite, arseniosiderite , zeunerite and bariopharmacosiderite . In some cases, nicellotharmeyerite is partially overgrown by tiny crusts of lukrahnite. Furthermore, light green konichalcite , beudantite and segnitite are given as accompanying minerals .

As a very rare mineral formation, nickellotharmeyerite could so far (as of 2018) only be described from five sites in three locations. In addition to the type locality of the “Pucherschacht”, this is also the “Am Roten Berg” mine field and the “Waldschacht” (“shaft 26”) in Schneeberg.

The second site in the world is the mining district of Bou Azzer near Taznakht (Tazenakht), Ouarzazate province in the Drâa-Tafilalet region in southern Morocco , where nickel-red armyerite in "Gang No. 52 ”was found in Aït Ahmane as a manganese-containing variety together with talmessite.

Finally, the mineral was also found in the mine "Km 3" west of Lavrion and not far from the village of Agios Konstantinos in the Lavrion District, Attica region , Greece . Here it was also described in the paragenesis of nickel sumorite - other companions are other nickel oxy salt minerals such as annabergite , nickelustinite , gaspéit and a Ni-dominant representative of the serpentine group , probably pecoraite .

Occurrences of nickellotharmeyerite in Austria or Switzerland are therefore not known.

use

Due to its rarity, nickellotharmeyerite is only of interest to mineral collectors.

See also

literature

  • Werner Krause, Herta Effenberger, Heinz-Jürgen Bernhardt, Mirko Martin: Cobalttsumcorite and nickellotharmeyerite, two new minerals from Schneeberg, Germany: description and crystal structure . In: New yearbook for mineralogy, monthly books . tape 2001 , no. 12 , 2001, p. 558-576 .

Web links

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

Individual evidence

  1. ↑ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj Werner Krause, Herta Effenberger, Heinz-Jürgen Bernhardt, Mirko Martin : Cobalttsumcorite and nickellotharmeyerite, two new minerals from Schneeberg, Germany: description and crytral structure . In: New yearbook for mineralogy, monthly books . tape 2001 , no. 12 , 2001, p. 558-576 .
  2. ↑ a b Mindat - Nickellotharmeyerite
  3. ^ August Frenzel : Mineralogical Lexicon for the Kingdom of Saxony . 1st edition. Verlag von Wilhelm Engelmann, Leipzig 1874, p.  43 ( available online in Mineralogical Lexicon for the Kingdom of Saxony. P. 43 in the Google book search).
  4. ↑ Werner Krause, Herta Effenberger, Heinz-Jürgen Bernhardt, Mirko Martin: Cobaltlotharmeyerite, Ca (Co, Fe, Ni) 2 (AsO 4 ) 2 (OH, H 2 O) 2 , a new mineral from Schneeberg, Germany . In: New yearbook for mineralogy, monthly books . tape 1999 , no. 11 , 1999, p. 505-517 .
  5. ↑ a b c d 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 .
  6. ↑ Type mineral catalog Germany - storage of the holotype and cotype stage Nickellotharmeyerit
  7. ↑ 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 , 1998, pp. 179-206 , doi : 10.1127 / ejm / 10/2/0179 .
  8. ↑ a b c Georges Favreau, Jacques Emile Dietrich: The minerals of Bou Azzer . In: Lapis . tape 31 , no. 7–8 , 2006, pp. 59 .
  9. ↑ a b c Stefan white: New minerals from Schneeberg / Saxony . In: Lapis . tape 27 , no. 7/8 , 2002, p. 73-76 .
  10. ↑ a b Igor V. Pekov, Nikita V. Chukanov, Dmitry A. Varlamov, Dmitry I. Belakovskiy, Anna G. Turchkova, Panagiotis Voudouris, Athanassios Katerinopoulos, Andreas Magganas: Nickeltsumcorite, Pb (Ni, Fe 3+ ) 2 (AsO 4 ) 2 (H 2 O, OH) 2 , a new tsumcorite-group mineral from Lavrion, Greece . In: Mineralogical Magazine . tape 80 , no. 2 , 2016, p. 337–346 , doi : 10.1180 / minmag.2016.080.003 .
  11. ↑ 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]).
  12. ↑ 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 .
  13. ^ A b Fritz Schlegel: New discoveries and new determinations from the mountain area Schneeberg / Saxony, 1990–2002 (II) . In: Lapis . tape 27 , no. 7/8 , 2002, p. 67-72 .
  14. ↑ Mindat - Number of localities for nickeltlotharmeyerite
  15. ↑ a b c List of locations where Nickellotharmeyerite was found in the Mineralienatlas and Mindat