Gartrellit
| Gartrellit | |
|---|---|
 |
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| General and classification | |
| other names |
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| chemical formula |
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Mineral class (and possibly department) |
Phosphates, arsenates and vanadates |
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System no. to Strunz and to Dana |
8.CG.20 ( 8th edition : VII / C.31) 02.33.02.01 |
| Similar minerals | Thometzekit, Zinc Gartrellite, Tsumcorite, Ferrilotharmeyerit and Beaverite |
| Crystallographic Data | |
| Crystal system | triclinic |
| Crystal class ; symbol | triclinic pinacoidal; 1 |
| Space group | P 1 (No. 2) |
| Lattice parameters |
a = 5.460 Å ; b = 5.653 Å; c = 7.589 Å α = 67.68 °; β = 69.27 °; γ = 70.04 ° |
| Formula units | Z = 1 |
| Frequent crystal faces | {111}, {010}, {112} |
| Twinning | often, with {1 1 0} as the twin plane |
| Physical Properties | |
| Mohs hardness | 4.5 (VHN 25 = 500 kg / mm 2 ) |
| Density (g / cm 3 ) | 5.38-5.43 (calculated) |
| Cleavage | very perfect after {111} |
| Break ; Tenacity | not specified; friable |
| colour | light yellow, greenish yellow, green, brown; pale yellow in transmitted light |
| Line color | light yellow |
| transparency | transparent |
| shine | earthy |
| Crystal optics | |
| Refractive indices |
n α = 1.94 n β = 1.98 (calculated) n γ = 2.06 |
| Birefringence | δ = 0.12 |
| Optical character | biaxial positive |
| Axis angle | 2V = 78 ° (measured), 74 ° (calculated) |
| Pleochroism | weak from X = Y = pale yellow to Z = yellow |
| Other properties | |
| Chemical behavior | slowly soluble in warm dilute HCl |
Gartrellite 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+ (AsO 4 ) 2 [(H 2 O) (OH)] and is therefore chemically seen a hydrous lead - copper - iron - arsenate with an additional hydroxy group .
Gartrellite is almost cryptocrystalline in its type locality and, according to {111}, develops tabular crystallites up to 10 μm in size as well as microcrystalline aggregates in the form of fine-grained coatings and powdery crusts. The type locality of the mineral is the copper prospectuses "Anticline" and "Bali Lo", Capricorn Range, Western Australia , Australia , located 11 km west-southwest of the Ashburton Downs homestead . The crystals described later from the "Tsumeb Mine" are much richer in shape and area and reach sizes of up to 0.1 mm.
Etymology and history
The Australian mineral collector Blair J. Gartrell (1950–1994) from Beverley / Australia, who collected the first samples of the mineral, is considered to be the discoverer of the Gartrellite. In the subsequent determinations, a new mineral was identified in this material. After intensive research by an Australian team of mineralogists and crystallographers led by Ernest H. Nickel , the new mineral was presented to the International Mineralogical Association (IMA), which recognized it as a new mineral in 1988. It was first described as a Gartrellite by Ernest H. Nickel, BW Robinson, J. FitzGerald and William D. Birch in the Australian science magazine "Australian Mineralogist" as early as 1989. The authors named the mineral after its finder.
Mineral phases, some of which later turned out to be gartrellite, had already been described in 1977 from the "Tsumeb Mine" in Namibia. These include a Pb-Fe-Cu-arsenate in the form of canary-yellow coatings under the provisional name "Mineral Gamma" and a Pb-Fe-Cu-Zn arsenate in dark green, tabular to flaky crystals on carminite under the provisional name "Mineral TK ". Gartrellit thus joins the considerable number of those species that were known from the "Tsumeb Mine" for a long time, but whose first description comes from another site.
Later it turned out that the mineral formula in the first description was incorrect due to the specified contents of carbonate groups. In 1998 Werner Krause, Klaus Belendorff, Heinz-Jürgen Bernhardt, Catherine McCammon, Herta Effenberger and Werner Mikenda redefined the Gartrellite recognized by the IMA.
The type material for Gartrellite (holotype) is stored under catalog number M39278 in the collection of the Melbourne Museum (formerly Museum Victoria) in Melbourne , Australia. Cotyp material is in the collection of the Western Australian Museum in Perth , Australia (catalog number M61.1991).
classification
The current classification of the International Mineralogical Association (IMA) counts the gartrellite 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 Gartrellit still Cabalzarit , Cobaltlotharmeyerit , Cobalttsumcorit , Ferrilotharmeyerit , Helmutwinklerit , Kaliochalcit , Krettnichit , Lotharmeyerit , Lukrahnit , Manganlotharmeyerit , Mawbyit , Mounanait , Natrochalcit , Nickellotharmeyerit , Nickelschneebergit , Nickeltsumcorit , Phosphogartrellit , 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 Gartrellit 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 , Helmutwinklerit , Krettnichit , Lotharmeyerit , Lukrahnit , Manganlotharmeyerit , Mawbyit , Mounanait , Nickellotharmeyerit , Nickelschneebergit , Phosphogartrellit , 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 Gartrellite 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 helmutwinklerite, lukrahnite, phosphogartrellite, 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 gartrellite to the class of "phosphates, arsenates and vanadates" and there in the department of "composite phosphates etc.". Here he is the namesake of the " Gartrellitgruppe " with the system no. 43.02.02 and the other members lukrahnite and zinc gartrellite within the sub-section "Compound phosphates etc., (water-containing, normally composed anions)".
Chemism
Fifteen microprobe analyzes on gartrellite showed mean values of 36.53% PbO; <0.05% CaO; 10.33% Fe 2 O 3 ; 0.11% Al 2 O 3 ; 0.21% ZnO; 14.02% CuO; 33.11% As 2 O 5 ; <0.05% V 2 O 5 ; <0.05% P 2 O 5 ; 1.68% SO 3 and 4.47% H 2 O (calculated content). From these, on the basis of 10 oxygen atoms, the empirical formula Pb 1.04 (Fe 0.82 Al 0.01 Zn 0.02 Cu 1.12 ) Σ = 1.97 [(AsO 4 ) 1.83 (SO 4 ) 0.13 ] Σ = 1.96 [(OH) 1.10 (H 2 O) 1.03 ] Σ = 2.13 , which leads to PbCuFe 3+ (AsO 4 ) 2 [(H 2 O) ( OH)] was idealized. The crystal chemical formula, which takes the two different Me (2) positions into account, can be written as PbCu (Fe 3+ , Cu) (AsO 4 ) 2 (OH, H 2 O) 2 .
Gartrellite is a representative of the tsumcorite group . The general formula for the tsumcorite group is Me (1) Me (2) 2 ( X O 4 ) 2 O (1) with Me (1) = Pb, Ca, Na, K and Bi; Me (2) = Fe, Mn, Cu, Zn, Co, Ni and Al; X = P, As, V and S as well as O (1) = H 2 O, OH and F. Mixed crystal formation takes place mainly on the Me (2) position, but less frequently on the X and Me (1) position . Gartrellite and zinc gartrellite form a mixed crystal series with the following structural formula: Pb (Zn x Fe 3+ 1 − x ) (Zn x Cu 1 − x ) (AsO 4 ) 2 (OH) 1 − x (H 2 O) 1 + x . In the Gartrellite the following applies for x: 0 <x <0.4. Crystals with 0.4 <x <-0.8 can be assigned to zinc gartrellite , while crystals with x ≈ 1.0 correspond to helmutwinklerite , which, however, differs from gartrellite and zinc gartrellite in certain structural features.
Since in Gartrellit on the Me (2) positions two sitting as well as trivalent cations, are on the O (1) position due to the necessity of a charge balancing considerable amounts of H 2 O by (OH) - substituted (hydroxy groups).
Gartrellite is the copper-dominant analogue of the zinc-dominated zinc gartrellite .
Crystal structure
Gartrellite crystallizes in the triclinic crystal system in the space group P 1 (space group no. 2) with the lattice parameters a = 5.460 Å ; b = 5.653 Å; c = 7.589 Å; α = 67.68 °; β = 69.27 ° and γ = 70.04 ° and one formula unit per unit cell .
The crystal structure of the Gartrellite consists of coordination polyhedra which are linked by common edges to form chains [010] parallel. AsO 4 - tetrahedra with common corners connect these chains, creating layers lying parallel to the ab surface. The layers are connected by hydrogen bonds and by Pb [6 + 2] atoms at the Me (1) position, which occupy specific positions with symmetry 1 between these layers. The Me (2) position is split as in the other representatives of the triclinic Tsumcoritgruppe in two different positions. As in zinc gartrellite, the triclinic symmetry of gartrellite 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.
The minerals of the tsumcorite group can be divided into three different subgroups (tsumcorite, helmutwinklerite and gartrellite subgroup), which are characterized by different structural types. Gartrellite is the eponymous representative of the Gartrellite subgroup, which is characterized by the orderly occupancy of the Me (2) position by cations with different crystal chemical behavior (here: Fe 3+ and Cu 2+ ). Considerable differences in the Zn contents are observed in the gartrellite-zinc gartrellite mixed crystal series. Chemical and structural data consistently show that Zn substitutes for Fe and Cu in almost equal amounts. The size of the triclinic distortion is controlled by the (Fe, Cu): Zn ratio. In the pure Zn end link, the Me (2) O 6 polyhedron is an octahedron . In this case the structure type changes to that of the Helmutwinklerite subgroup.
Gartrellite is isotypic (isostructural) to zinc gartrellite , but not to helmutwinklerite.
properties
morphology
Gartrellite develops tabular crystallites approx. 10 µm in size at the {111} type locality. At other localities (Reichenbach, Odenwald, and Tsumeb, Namibia) it occurs in up to 0.1 mm large, quite extensive, also tabular crystals up to 0.3 mm in size according to {111}. The pinacoids {010}, {001}, {01 1 }, {01 2 }, {110}, {112} and possibly also {100} have been identified on these crystals . Gartrellite often forms twins with {1 1 0} as the twin plane (compare the crystal drawing opposite). It is also found in microcrystalline aggregates in the form of fine-grained coatings and powdery crusts.
physical and chemical properties
The crystals of the Gartrellite are characterized by a large variety of colors. Yellow, brown and green varieties with different color transitions were described. The line color of the Gartrellite, on the other hand, is always light yellow. According to the values for the refraction of light (n x = 1.94, n z = 2.06), the surfaces of the transparent crystals have a glass-like to diamond-like sheen . Gartrellite of the type locality has no real shine due to the crystal size, but is earthy to chalky. Under the microscope the mineral shows pale yellow hues and a weak pleochroism from X = Y = pale yellow to Z = yellow.
The mineral has a very perfect cleavage according to (111). 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 between 5.38 and 5.43 g / cm³, depending on the author.
Gartrellite slowly dissolves in warm dilute hydrochloric acid (HCl).
Education and Locations
Gartrellite is a typical secondary mineral , which is formed by weathering of primary ore minerals in the oxidation zone of ore deposits of different genetic positions. At the type locality "Anticline Prospect" it is found in a mineralized and oxidized shear zone settled by greywacke and shale , in Broken Hill , Australia, it occurs on a fine-grained quartz - spessartine rock. In the world-famous Cu-Pb-Zn-Ag-Ge-Cd deposit of the "Tsumeb Mine" (Tsumcorp Mine) in Tsumeb , Oshikoto region , Namibia , it was formed from lead and copper-containing sulfides such as galena and chalcocine , with arsenic comes from the decomposition of the arsenic ore tennantite .
Paragenesis minerals from the original find in the “Anticline Prospect” are secondary copper minerals, quartz, clay minerals and iron oxides. In "Broken Hill", Gartrellite is accompanied by drusy brown hidalgoite - Beudantite as well as quartz and Spessartine. In the "Tsumeb Mine" it occurs together with mimetesite , fragranceite , beudantite, tabular bayldonite , olivite , quartz and carminite.
As of 2017, Gartrellite could only be described as a rare mineral formation from around 40 sites. As type locality , the 11 copper brochures "Anticline" (Mineral Claim 84 Cu deposit) km west-southwest past the homestead Ashburton Downs (valid coordinates of copper prospectus Anticline ) and "Bali Lo" (Casleys Prospect), Shire of Ashburton , Capricorn Range, Western Australia, Australia. The appearance of Gartrellit in the “Kintore Opencut” of the famous “Broken Hill” deposit (Broken Hill South Mine) near the place of the same name in Yancowinna Co., New South Wales , Australia, was also mentioned in the type publication . Gartrellite was also found in the Cu-Au open pit mine of the "New Cobar Mine" near Cobar , Robinson Co., New South Wales, Australia. The world's best representatives of this type of mineral, however, come from the "Tsumeb Mine" in Namibia, where Gartrellite was found here in the first (upper), second (lower) and also in the so-called third oxidation zone.
In Germany , Gartrellite is known from the “Silberbrünnle” mine in the Haigerach Valley near Gengenbach , from the “Lisbühl” near Todtnau and from the Clara mine in the Rankach Valley near Oberwolfach , all in the Black Forest , Baden-Württemberg . Also from the “Schöne Aussicht” mine, Dernbach near Neuwied in the Siegerland-Wied district , Westerwald , Rhineland-Palatinate . Finally from point 5.0 and from point 8.0 in a silicified barite trough on the Borstein cliff near Reichenbach , a district of Lautertal in the Hessian Odenwald , as well as from four other points in the same barite trough in the vicinity of the Hohenstein and the Teufelsstein. Locations for Gartrellit in Austria and Switzerland are not known.
In Europe, more finds were made at the “Shaft No. 132 "of the" Christiana Mine ", in the" Hilarion Mine "and on the large Kamariza heaps, all near Agios Konstantinos (Kamariza) in the Lavrion District, Attica region , Greece . Also from the "Bakara" mine in the Balkan Mountains (Stara Planina), Oblast Wraza , the copper deposit Zapachitsa near Bov, municipality Swoge , Oblast Sofia , both in Bulgaria , and from "Likas kő" on Meleg hill near Lovasberény in the Velencei mountains, Fejér County , Hungary . In Italy from the old Cu-Ag mine of the "Miniera di Monte Avanza" near Forni Avoltri , Friuli-Venezia Giulia , and from the famous "Miniera Baccu Locci" near Villaputzu , province of Sud Sardegna in Sardinia . In France from the “Mine du Cap Garonne” near Le Pradet, Var , Provence-Alpes-Côte d'Azur region , from the vein-like deposit “Falgayrolles” near Monteils , Aveyron department , Occitania , from the “Mine du Donnerloch” on the Schletzelberg near Silberthal, Steinbach, Cernay , Département Haut-Rhin , Region Grand Est , as well as from the corridors “Filon du Mazet” and “Filon Ste Barbe” in the “Mine des Montmins”, Échassières , Ébreuil , Département Allier , Auvergne . Finally in Spain from the "Mina La Estrella" in the Jaroso Gorge in the Sierra Almagrera, Cuevas del Almanzora, as well as from the old gold mine of the "Mina Sol" (Mina La Milagrosa) on the Cerro de los Guardias near Rodalquilar in the Níjar district , both near Almería , Andalusia . In the United Kingdom from the "Dolyhir Quarry" near Wethel not far from Old Radnor , Powys in Wales .
In Chile from the "Mina Jote" in the Pampa Larga District (Tierra Amarilla), Copiapó Province , Región de Atacama . Finally in the United States from the "Emerald Mine" belonging to the Emerald & Silver Plume Mine Group in the Tombstone Hills , Tombstone District, Cochise County , Arizona , from the "Black Pine Mine", Black Pine Ridge in the John Long Mts. in the Philipsburg District, Granite County , Montana , and from the Centennial Eureka Mine and Trixie Mine in East Tintic Mts. in the Tintic District, Juab Co. , and "Gold Hill" in Deep Creek Mts., Tooele Co. , all in Utah .
use
Because of its rarity, Gartrellite is only of interest to mineral collectors.
See also
literature
- 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 .
- 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 .
- Gartrellite . 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 March 11, 2017]).
Web links
- Mineral Atlas: Gartrellite (Wiki)
- Mindat - Gartrellit (English)
- Webmineral - Gartrellit (English)
- RRUFF Database-of-Raman-spectroscopy - Gartrellit (English)
- American-Mineralogist-Crystal-Structure-Database - Gartrellit (English)
Individual evidence
- ↑ 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 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 .
- ↑ 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 / 2002 / 0014-0115 .
- ^ 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 .
- ↑ a b c d e f 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 .
- ↑ a b c Mindat - Gartrellit
- ↑ a b c www.tsumeb.com - Gartrellit
- ↑ a b c d e f Gartrellite . 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 March 11, 2017]).
- ↑ William B. Pinch, Wendell E. Wilson: Minerals: a descriptive list . In: The Mineralogical Record . tape 8 , no. 3 , 1977, pp. 17-37 .
- ↑ Paul Keller: Tsumeb / Namibia - one of the most spectacular mineral discovery sites on earth . In: Lapis . tape 9 , no. 7/8 , 1984, pp. 13-63 .
- ↑ a b Georg Gebhard: Tsumeb . 1st edition. GG Publishing, Grossenseifen 1999, p. 252-253 .
- ↑ Catalog of Type Mineral Specimens - G. (PDF 77 kB) In: docs.wixstatic.com. Commission on Museums (IMA), December 12, 2018, accessed August 29, 2019 .
- ↑ a b c d e 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 ]).
- ↑ Mindat - Number of localities for Gartrellit
- ↑ a b List of localities for Gartrellit in the Mineralienatlas and Mindat