Phosphogartrellite

from Wikipedia, the free encyclopedia
Phosphogartrellite
General and classification
other names

IMA 1996-035

chemical formula
  • PbCuFe 3+ (PO 4 ) 2 (OH) ∙ H 2 O
  • Pb (Cu, Fe 3+ ) 2 (PO 4 , AsO 4 ) 2 2 (H 2 O, OH)
  • PbCuFe 3+ (PO 4 ) 2 (OH, H 2 O) 2
  • PbCuFe [H 2 O | OH | (PO 4 ) 2 ]
Mineral class
(and possibly department) 		Phosphates, arsenates and vanadates
System no. to Strunz
and to Dana 		8.CG.20 ( 8th edition : VII / C.31)
02.02.05.01
Crystallographic Data
Crystal system triclinic
Crystal class ; symbol triclinic pinacoidal; 1
Space group P 1 (No. 2)Template: room group / 2
Lattice parameters a  = 5.320  Å ; b  = 5.528 Å; c  = 7.434 Å,
α  = 67.61 °; β  = 69.68 °; γ  = 70.65 °
Formula units Z  = 1
Physical Properties
Mohs hardness 4.5
Density (g / cm 3 ) 5.05 (calculated)
Cleavage no
Break ; Tenacity not specified; not specified
colour light greenish
Line color yellow
transparency translucent to transparent (only small fragments)
shine Glass to diamond gloss
Crystal optics
Refractive indices n α  = 1.900
n β  = 1.930 (calculated)
n γ  = 2.000
Birefringence δ = 0.100
Optical character biaxial positive
Axis angle 2V = 70 ° (measured), 70 ° (calculated)
Pleochroism not pleochroic
Other properties
Chemical behavior Completely soluble in warm dilute HCl and without effervescence

Phosphogartrellite is a rarely occurring mineral from the mineral class of " phosphates , arsenates and vanadates ". It crystallizes in the triclinic crystal system with the chemical composition PbCuFe 3+ (PO 4 ) 2 (OH) ∙ H 2 O and is therefore chemically a water-containing lead - copper - iron - phosphate with an additional hydroxide ion . At its type locality, phosphogartrellite develops tiny, parallel intergrown, steeply terminated crystals up to a maximum of 50 μm in length and aggregates composed of them up to 0.2 mm in size. The type locality of the mineral is a silicified barite dike, approx. 200 m south of the Hohenstein cliff near Reichenbach , a district of Lautertal (Odenwald) in the Odenwald , Hesse , Germany .

Etymology and history

During the processing of secondary minerals from a silicified barite vein near Reichenbach in the Odenwald, a mineral was identified which, although a phosphate, turned out to be a new representative of the minerals of the tsumcorite group. After the necessary further investigations by a team of German mineralogists and crystallographers around Werner Krause, the new mineral was presented to the International Mineralogical Association (IMA), which recognized it as a new mineral in 1996. As early as 1998, it was first described as a phosphogartrellite by Werner Krause, Klaus Belendorff, Heinz-Jürgen Bernhardt and Klaus Petitjean in the German science magazine "New Yearbook for Mineralogy, MONTHS". The authors named the mineral phosphogartrellite after its phosphorus content and its crystal-chemical relationship with gartrellite. The type material for phosphogartrellite (holotype) is kept in the collection of the Institute for Mineralogy, Geology and Geophysics of the Ruhr University Bochum in Bochum , North Rhine-Westphalia .

classification

The current classification of the International Mineralogical Association (IMA) counts the phosphogartrellite 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 Phosphogartrellit still Cabalzarit , Cobaltlotharmeyerit , Cobalttsumcorit , Ferrilotharmeyerit , Gartrellit , Helmutwinklerit , Kaliochalcit , Krettnichit , Lotharmeyerit , Lukrahnit , Manganlotharmeyerit , Mawbyit , Mounanait , Natrochalcit , Nickellotharmeyerit , Nickelschneebergit , Nickeltsumcorit , Rappoldit , Schneebergit , Thometzekit , Tsumcorit , Yancowinnait and Zinc Gartrellite .

In the meantime outdated, but still in use 8th edition of the mineral classification by Strunz of Phosphogartrellit belonged to the mineral class of "phosphates, arsenates and vanadates" and then to the Department of "water containing phosphates without foreign anions " where he along with Cabalzarit , Cobaltlotharmeyerit , Cobalttsumcorit , Ferrilotharmeyerit , Gartrellit , Helmutwinklerit , Krettnichit , Lotharmeyerit , Lukrahnit , Manganlotharmeyerit , Mawbyit , Mounanait , Nickellotharmeyerit , Nickelschneebergit , Rappoldit , Schneebergit , Thometzekit , Tsumcorit and Zinkgartrellit the "Tsumcorit-Gartrellit group" with the system number. 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 the phosphogartrellite 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 the other members gartrellite, helmutwinklerite, lukrahnite, rappoldite and zinc gartrellite the" Helmutwinklerite group "with the system no. 8.CG.20 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the phosphogartrellite to the class of "phosphates, arsenates and vanadates" and there in the section of "composite phosphates, etc.". Here he is the only member of the unnamed group 02.02.05 within the subdivision of " Water-containing phosphates etc., with hydroxyl or halogen with (AB) 3 (XO 4 ) Z q × x (H 2 O) ".

Chemism

Twelve microprobe analyzes on Phosphogartrellite resulted in mean values ​​of 39.02% PbO; 0.20% CaO; 14.14% Fe 2 O 3 ; 14.41% CuO; 22.05% P 2 O 5 ; 4.58% As 2 O 5 and 4.83% H 2 O (calculated content). The empirical formula (Pb 0.99 Ca 0.02 ) Σ = 1.01 Cu 1.02 Fe 1.00 [(PO 4 ) 1.75 (AsO 4 ) 0, is calculated from them on the basis of 10 oxygen atoms . 23 ] Σ = 1.98 [(OH) 1.12 (H 2 O) 0.96 ] Σ = 2.08 , which was idealized to PbCuFe 3+ (PO 4 ) 2 (OH) ∙ H 2 O. This requires levels of 40.46% PbO; 14.48% Fe 2 O 3 ; 14.42% CuO; 25.74% P 2 O 5 and 4.90% H 2 O. Since the Cu: Fe 3+ ratio is almost 1: 1, formally equal amounts of (OH) and (H 2 O) are present. Nevertheless, both molecules can also be written in brackets (OH, H 2 O), since both are in the same crystallographic position, which, however, requires the notation as an H 3 O 2 group. Although not verified by microprobe analyzes, it is likely that the mixed crystal series found for gartrellite also applies to phosphogartrellite, i.e. that copper substitutes at least parts of iron and zinc substitutes both copper and iron. Therefore, a general formula for phosphogartrellite must be Pb (Cu, Zn) (Fe, Cu, Zn) (PO 4 ) 2 (OH, H 2 O) 2 . In addition to solid solution formation on the Me (2) position, solid solution formation on the X position is also achieved in the phosphogartrellite due to the high arsenate content .

Phosphogartrellite is the phosphate-dominant analogue of the arsenate-dominated gartrellite.

Crystal structure

Phosphogartrellite crystallizes in the triclinic crystal system in the space group P 1 (space group no. 2) with the lattice parameters a  = 5.320  Å ; b  = 5.528 Å; c  = 7.434 Å; α = 67.61 °; β = 69.68 ° and γ = 70.65 ° and one formula unit per unit cell . Template: room group / 2

Phosphogartrellite is isotypic (isostructural) to Gartrellite. As a result, the crystal structure is identical to that of Gartrellite and that of the other triclinic representatives of the tsumcorite group, as described by Herta Effenberger and co-authors. It consists of coordination polyhedra that are linked by common edges to form chains parallel [010]. PO 4 - tetrahedra with common corners connect these chains, creating layers parallel to the ab-surface. The layers are connected by hydrogen bonds and by Pb [6 + 2] atoms at the Me (1) position. The Me (2) position is split as in the other representatives of the triclinic Tsumcoritgruppe in two different positions. As in gartrellite or zinc gartrellite, the triclinic symmetry of phosphoartrellite is caused by the different stereochemical requirements of iron and copper. The splitting of the Me (2) position into two positions, Me (2a) and Me (2b), allows the assumption of different crystal-chemical environments: The coordination polyhedron Me (2a) [4 + 2] O 6 is distorted because the Cu 2 + Atoms prefer the tetragonal-bipyramidal [4 + 2] coordination due to their electron configuration caused by the Jahn-Teller effect . For the coordination polyhedron Me (2b) [6] O 6 , however, the octahedral coordination, which is favored by the Fe 3+ atoms, is retained.

properties

morphology

Phosphogartrellite develops aggregates up to 0.2 mm in diameter at the type locality, which consist of parallel, intergrown, steeply terminated single crystals up to a maximum of 50 µm in length.

physical and chemical properties

The crystals and aggregates of Phosphogartrellite are light greenish, while their line color is always light yellow. The surfaces of the translucent phosphogartellites, which are only transparent in small fragments, have a glass-like to diamond-like sheen , which goes well with the very high values ​​for light refraction (n α  = 1.900; n β  = 1.930; n γ  = 2.000) and for birefringence (δ = 0.100) of the Phosphogartrellite corresponds. Under the microscope , the mineral shows no pleochroism in transmitted light .

The mineral has no visible cleavage . Information on tenacity and breakage is missing. With a Mohs hardness of 4.5, Gartrellite is one of the medium-hard minerals, which means 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 calculated density of the mineral is 5.05 g / cm³. The mineral is neither in the long term nor in the short wavelength UV light , a fluorescent .

Gartrellite is completely soluble in warm dilute hydrochloric acid , HCl, and without fizz.

Education and Locations

Phosphogartrellite is a typical secondary mineral which is formed by weathering of primary ore minerals in the oxidation zone of ore deposits . At the type locality, a silicified barite dike sitting in crystalline slate , it was probably formed by decomposition from primary ore minerals such as galena , chalcopyrite , tennantite , emplektite and / or wittichenite .

Paragenesis minerals from the original find are also arsenic, dark green hentschelite , pyromorphite , turquoise-green malachite and cuprite .

As a very rare mineral formation, phosphogartrellite could so far (as of 2018) only be described from four separate sites in the same find area. The type locality is "Fundpunkt 15.1", a silicified barite dike, approx. 200 m south of the Hohenstein cliff near Reichenbach , a district of Lautertal (Odenwald) in the Odenwald , Hesse , Germany . These are outcrops and loose debris in the Vorbachtal south of the Hohenstein cliff that was dismantled by Walther GmbH from Gadernheim between 1993 and 1994 . Another locality is the nearby "Fundpunkt 14.0" - a discarded and recultivated quartz quarry west of the Hohenstein cliff in the same silicified barite dike as the " Fundpunkt " , worked 1962–1964 by the company DESTAG from Reichenbach and 1996–1997 by Walther GmbH from Gadernheim 15.1 ". Also from "Fundpunkt 20.0" on the Katzenstein cliff near Raidelbach not far from Lautertal (Odenwald). This is also a disused quarry in a silicified barite dike, which was worked from 1978 to 1982 by Helmut Walter GmbH from Gadernheim and recultivated as early as 1984–1985.

Finally also from the locality "Bergweg" near Gadernheim, Lautertal (Odenwald), also in the Hessian Odenwald.

use

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

See also

literature

  • Werner Krause, Klaus Belendorff, Heinz-Jürgen Bernhardt, Klaus Petitjean: Phosphogartrellite, PbCuFe 3+ (PO 4 ) 2 (OH) ∙ H 2 O, a new member of the tsumcorite group . In: New yearbook for mineralogy, monthly books . tape 1998 , no. 3 , 1998, p. 111-118 .
  • 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 .
  • Phosphogartrellite . 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 June 1, 2018]).

Web links

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 ak al Werner Krause, Klaus Belendorff, Heinz-Jürgen Bernhardt, Klaus Petitjean: Phosphogartrellite, PbCuFe 3+ (PO 4 ) 2 (OH) ∙ H 2 O, a new member of the tsumcorite group . In: New yearbook for mineralogy, monthly books . tape 1998 , no. 3 , 1998, p. 111-118 .
  2. ↑ a b c Mindat - Phosphogartrellite
  3. ↑ a b c Phosphogartrellite . 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 June 1, 2018]).
  4. ^ 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.  484 .
  5. ^ A b Ernest H. Nickel , BW Robinson, O. Fitz Gerald, William D. Birch: Gartrellite, a new secondary arsenate mineral from Ashburton Downs, WA and Broken Hill, NSW In: Australian Mineralogist . tape  4 , 1989, pp. 83-89 .
  6. ↑ Type mineral catalog Germany - storage of the type level Phosphogartrellite
  7. ↑ Catalog of Type Mineral Specimens - P. (PDF 113 kB) In: docs.wixstatic.com. Commission on Museums (IMA), December 12, 2018, accessed August 29, 2019 .
  8. ↑ 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 , 1998, pp. 179-206 , doi : 10.1127 / ejm / 10/2/0179 .
  9. ↑ a b Herta Effenberger, Werner Krause, Heinz-Jürgen Bernhardt, Mirko Martin: On the symmetry of tsumcorite group minerals based on the new species rappoldite and zincgartrellite . In: Mineralogical Magazine . tape 64 , no. 6 , 2000, pp. 1109–1126 , doi : 10.1180 / 002646100549922 ( rruff.info [PDF; 1.1 MB ]).
  10. ↑ Mindat - Number of sites for phosphogartrellite
  11. ↑ Find location list for Gartrellit at the Mineralienatlas and at Mindat
  12. ↑ Mindat - description of the place of discovery find point 15.1 near Reichenbach
  13. ↑ Mindat - description of the place of discovery find point 14.0 near Reichenbach
  14. ^ Klaus Petitjean, Klaus Belendorff: Reichenbach in the Odenwald: The minerals from the point of discovery 14.0 . In: Lapis . tape 25 , no. 2 , 2000, pp. 13-30 .
  15. ^ Klaus Belendorff, Klaus Petitjean: Reichenbach in the Odenwald: The minerals from the discovery point 16.1 near Reichenbach . In: Lapis . tape 12 , no. 10 , 1987, pp. 23-32 .
  16. ↑ Mindat - description of the location of point 14.0 at Raidelbach
  17. ↑ Mindat - description of the location of the mountain path near Gadernheim