Ritsuro Miyawaki, Frédéric Hatert, Marco Pasero, Stuart J. Mills
Ritsuro Miyawaki, (Chairman, CNMNC)1, Frédéric Hatert, (Vice-Chairman, CNMNC)2, Marco Pasero, (Vice-Chairman, CNMNC)3 and Stuart J. Mills, (Secretary, CNMNC)4 1 Department of Geology, National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba 305-0005, Japan – miyawaki@kahaku.go.jp; 2 Laboratoire de Minéralogie, Université de Liège, Bâtiment B18, Sart Tilman, 4000 Liège, Belgium – fhatert@uliege.be; 3 Dipartimento di Scienze della Terra, Università di Pisa, Via Santa Maria 53, 56126 Pisa, Italy – marco.pasero@unipi.it; and 4 Geosciences, Museums Victoria, PO Box 666, Melbourne, Victoria 3001, Australia – smills@museum. vic.gov.au
{"title":"Newsletter 70","authors":"Ritsuro Miyawaki, Frédéric Hatert, Marco Pasero, Stuart J. Mills","doi":"10.1180/mgm.2022.135","DOIUrl":"https://doi.org/10.1180/mgm.2022.135","url":null,"abstract":"Ritsuro Miyawaki, (Chairman, CNMNC)1, Frédéric Hatert, (Vice-Chairman, CNMNC)2, Marco Pasero, (Vice-Chairman, CNMNC)3 and Stuart J. Mills, (Secretary, CNMNC)4 1 Department of Geology, National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba 305-0005, Japan – miyawaki@kahaku.go.jp; 2 Laboratoire de Minéralogie, Université de Liège, Bâtiment B18, Sart Tilman, 4000 Liège, Belgium – fhatert@uliege.be; 3 Dipartimento di Scienze della Terra, Università di Pisa, Via Santa Maria 53, 56126 Pisa, Italy – marco.pasero@unipi.it; and 4 Geosciences, Museums Victoria, PO Box 666, Melbourne, Victoria 3001, Australia – smills@museum. vic.gov.au","PeriodicalId":18618,"journal":{"name":"Mineralogical Magazine","volume":"87 1","pages":"160 - 168"},"PeriodicalIF":2.7,"publicationDate":"2023-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47134938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. R. Kampf, S. Mills, B. Nash, M. Dini, A. A. M. Donoso
Abstract The new mineral alumolukrahnite (IMA2022–059), CaCu2+Al(AsO4)2(OH)(H2O), was found at the Jote mine, Copiapó Province, Chile, where it is a secondary alteration phase associated with conichalcite, coronadite, gypsum, olivenite, pharmacosiderite, rruffite and scorodite. Alumolukrahnite occurs as crude diamond-shaped tablets up to ~0.1 mm, intergrown in crude spherical aggregates. Crystals are apple green and transparent to translucent, with vitreous lustre and a white streak. The Mohs hardness is 3½. The mineral is brittle with irregular fracture and no cleavage. The calculated density is 4.094 g cm–3. Optically, alumolukrahnite is biaxial (+) with α = 1.73(1), β = 1.74(1) and γ = 1.76(1) (white light). The empirical formula, determined from electron microprobe analyses, is Ca1.01(Cu0.92Zn0.13)Σ1.05(Al0.96Fe0.01)Σ0.97(As0.985O4)2(OH)0.88(H2O)1.12. Alumolukrahnite is triclinic, P$bar{1}$, a = 5.343(5), b = 5.501(5), c = 7.329(5) Å, α = 67.72(2), β = 69.06(2), γ = 69.42(2)°, V = 180.3(3) Å3 and Z = 1. Alumolukrahnite is a member of the tsumcorite group and is the Al analogue of lukrahnite.
{"title":"Alumolukrahnite, CaCu2+Al(AsO4)2(OH)(H2O), the aluminium analogue of lukrahnite from the Jote mine, Copiapó Province, Chile","authors":"A. R. Kampf, S. Mills, B. Nash, M. Dini, A. A. M. Donoso","doi":"10.1180/mgm.2022.142","DOIUrl":"https://doi.org/10.1180/mgm.2022.142","url":null,"abstract":"Abstract The new mineral alumolukrahnite (IMA2022–059), CaCu2+Al(AsO4)2(OH)(H2O), was found at the Jote mine, Copiapó Province, Chile, where it is a secondary alteration phase associated with conichalcite, coronadite, gypsum, olivenite, pharmacosiderite, rruffite and scorodite. Alumolukrahnite occurs as crude diamond-shaped tablets up to ~0.1 mm, intergrown in crude spherical aggregates. Crystals are apple green and transparent to translucent, with vitreous lustre and a white streak. The Mohs hardness is 3½. The mineral is brittle with irregular fracture and no cleavage. The calculated density is 4.094 g cm–3. Optically, alumolukrahnite is biaxial (+) with α = 1.73(1), β = 1.74(1) and γ = 1.76(1) (white light). The empirical formula, determined from electron microprobe analyses, is Ca1.01(Cu0.92Zn0.13)Σ1.05(Al0.96Fe0.01)Σ0.97(As0.985O4)2(OH)0.88(H2O)1.12. Alumolukrahnite is triclinic, P$bar{1}$, a = 5.343(5), b = 5.501(5), c = 7.329(5) Å, α = 67.72(2), β = 69.06(2), γ = 69.42(2)°, V = 180.3(3) Å3 and Z = 1. Alumolukrahnite is a member of the tsumcorite group and is the Al analogue of lukrahnite.","PeriodicalId":18618,"journal":{"name":"Mineralogical Magazine","volume":"87 1","pages":"465 - 469"},"PeriodicalIF":2.7,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44486738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ginga Kitahara, A. Yoshiasa, S. Ishimaru, Kunihisa Terai, M. Tokuda, D. Nishio–Hamane, Takahiro Tanaka, K. Sugiyama
Abstract Rh-rich and Ir-poor erlichmanite–laurite OsS2–RuS2 solid solutions have been discovered at placers in Haraigawa, Misato-machi, Kumamoto, Japan. Microprobe analysis was performed to identify solid solutions containing few sub-components other than Rh. Approximately 10 at.% Rh was found to be present in the solid-solution samples. Structural refinement was performed using four natural samples: Os0.32Ru0.61Rh0.07S2, Os0.49Ru0.43Rh0.08S2, Os0.58Ru0.33Rh0.08S2 and Os0.81Ru0.09Rh0.10S2. The unit-cell parameters for the solid solutions containing Rh from Haraigawa varied from 5.61826(6) to 5.63142(8) Å. The (Os, Ru, Rh)–S distances in the Os1–x–yRuxRhyS2 system were almost constant with a small variation of 0.001 Å. Conversely, the S–S distances varied significantly, with variations approaching 0.1 Å. Rh substitution of Os rather than Ru had a larger impact on the crystal structure. The atomic displacement ellipsoid of both cations and anions was almost spherical, and no elongation along the M–S and S–S bond directions was observed. The bulk Debye temperatures were estimated from the Debye–Waller factor for the sulfide site. The bulk Debye temperatures of pure OsS2 and RuS2 were 688 K and 661 K, respectively, which suggests that the melting point of erlichmanite is higher than that of laurite. The high Debye temperature of OsS2 is inconsistent with the crystallisation of laurite prior to erlichmanite from the primitive magma, which suggests that $f_{rm S_2}$, rather than temperature, is the main cause of the known crystallisation order. The presence of several percent Rh has a significant effect on the thermal stability of OsS2 and lowers the melting point of the erlichmanite solid solution compared to that of the laurite solid solution.
{"title":"Crystal structures of rhodium-containing erlichmanite–laurite solid solutions (Os1–x–yRuxRhyS2: x = 0.09–0.60, y = 0.07–0.10) with unique compositional dependence","authors":"Ginga Kitahara, A. Yoshiasa, S. Ishimaru, Kunihisa Terai, M. Tokuda, D. Nishio–Hamane, Takahiro Tanaka, K. Sugiyama","doi":"10.1180/mgm.2022.139","DOIUrl":"https://doi.org/10.1180/mgm.2022.139","url":null,"abstract":"Abstract Rh-rich and Ir-poor erlichmanite–laurite OsS2–RuS2 solid solutions have been discovered at placers in Haraigawa, Misato-machi, Kumamoto, Japan. Microprobe analysis was performed to identify solid solutions containing few sub-components other than Rh. Approximately 10 at.% Rh was found to be present in the solid-solution samples. Structural refinement was performed using four natural samples: Os0.32Ru0.61Rh0.07S2, Os0.49Ru0.43Rh0.08S2, Os0.58Ru0.33Rh0.08S2 and Os0.81Ru0.09Rh0.10S2. The unit-cell parameters for the solid solutions containing Rh from Haraigawa varied from 5.61826(6) to 5.63142(8) Å. The (Os, Ru, Rh)–S distances in the Os1–x–yRuxRhyS2 system were almost constant with a small variation of 0.001 Å. Conversely, the S–S distances varied significantly, with variations approaching 0.1 Å. Rh substitution of Os rather than Ru had a larger impact on the crystal structure. The atomic displacement ellipsoid of both cations and anions was almost spherical, and no elongation along the M–S and S–S bond directions was observed. The bulk Debye temperatures were estimated from the Debye–Waller factor for the sulfide site. The bulk Debye temperatures of pure OsS2 and RuS2 were 688 K and 661 K, respectively, which suggests that the melting point of erlichmanite is higher than that of laurite. The high Debye temperature of OsS2 is inconsistent with the crystallisation of laurite prior to erlichmanite from the primitive magma, which suggests that $f_{rm S_2}$, rather than temperature, is the main cause of the known crystallisation order. The presence of several percent Rh has a significant effect on the thermal stability of OsS2 and lowers the melting point of the erlichmanite solid solution compared to that of the laurite solid solution.","PeriodicalId":18618,"journal":{"name":"Mineralogical Magazine","volume":"87 1","pages":"396 - 406"},"PeriodicalIF":2.7,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43546643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Synthetic samples of krautite, Mn[AsO3(OH)]⋅H2O, koritnigite, Zn[AsO3(OH)]⋅H2O and cobaltkoritnigite, Co[AsO3(OH)]⋅H2O, were used for calorimetric experiments. For krautite and koritnigite, single-crystal X-ray diffraction was used to determine positions of all atoms, including the H atoms. These data allowed the hydrogen-bond network and the function of H2O molecules in these structures to be determined. The structural formulae are Mn4(H2[3]O)4[AsO3(OH)]4 and Zn4(H2[3]O)2[AsO3(OH)]4(H2[4]O)2, where [3]H2O and [4]H2O are the ‘transformer’ and ‘non-transformer’ H2O groups, respectively. Even though the principal features of these structures are identical, the details, especially those regarding the H2O groups, differ from one structure to another structure in this group. The solubility products (log Ksp) were determined from calorimetric data, that is, from the experimentally measured enthalpies of formation and entropies. They relate to the reaction M[AsO3(OH)]⋅H2O → M2+ + HAsO42– + H2O and are –6.10 for krautite, –6.88 for koritnigite and –6.83 for cobaltkoritnigite. We also estimated the log Ksp for magnesiokoritnigite as –2.0. Calculation of phase diagrams shows that all these phases originate under acidic conditions from solutions with high metal and arsenate concentration. They are restricted to local environments, to pockets that maintain such high concentrations over the time necessary for crystallisation of the krautite-group phases.
{"title":"Thermodynamics and crystal structures of krautite, Mn[AsO3(OH)]⋅H2O, koritnigite, Zn[AsO3(OH)]⋅H2O and cobaltkoritnigite, Co[AsO3(OH)]⋅H2O","authors":"J. Majzlan, J. Plášil, E. Dachs","doi":"10.1180/mgm.2022.140","DOIUrl":"https://doi.org/10.1180/mgm.2022.140","url":null,"abstract":"Abstract Synthetic samples of krautite, Mn[AsO3(OH)]⋅H2O, koritnigite, Zn[AsO3(OH)]⋅H2O and cobaltkoritnigite, Co[AsO3(OH)]⋅H2O, were used for calorimetric experiments. For krautite and koritnigite, single-crystal X-ray diffraction was used to determine positions of all atoms, including the H atoms. These data allowed the hydrogen-bond network and the function of H2O molecules in these structures to be determined. The structural formulae are Mn4(H2[3]O)4[AsO3(OH)]4 and Zn4(H2[3]O)2[AsO3(OH)]4(H2[4]O)2, where [3]H2O and [4]H2O are the ‘transformer’ and ‘non-transformer’ H2O groups, respectively. Even though the principal features of these structures are identical, the details, especially those regarding the H2O groups, differ from one structure to another structure in this group. The solubility products (log Ksp) were determined from calorimetric data, that is, from the experimentally measured enthalpies of formation and entropies. They relate to the reaction M[AsO3(OH)]⋅H2O → M2+ + HAsO42– + H2O and are –6.10 for krautite, –6.88 for koritnigite and –6.83 for cobaltkoritnigite. We also estimated the log Ksp for magnesiokoritnigite as –2.0. Calculation of phase diagrams shows that all these phases originate under acidic conditions from solutions with high metal and arsenate concentration. They are restricted to local environments, to pockets that maintain such high concentrations over the time necessary for crystallisation of the krautite-group phases.","PeriodicalId":18618,"journal":{"name":"Mineralogical Magazine","volume":"87 1","pages":"194 - 203"},"PeriodicalIF":2.7,"publicationDate":"2022-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46470088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Mikuš, Jozef Vlasáč, J. Majzlan, J. Sejkora, G. Steciuk, J. Plášil, C. Rößler, Christian Matthes
Abstract Argentotetrahedrite-(Cd), Ag6(Cu4Cd2)Sb4S13, has been approved as a new mineral species by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association using samples from Rudno nad Hronom, Slovak Republic. It occurs as anhedral grains up to 30 μm in size, steel-grey to black in colour, with a metallic lustre, in association with greenockite and other tetrahedrite-group minerals [argentotetrahedrite-(Zn) and tetrahedrite-(Zn)], earlier base-metal minerals, Ag sulfides and sulfosalts (acanthite, pyrargyrite and polybasite) and later galena. Argentotetrahedrite-(Cd) is isotropic, grey in colour, with a creamy tint and rapidly (tens of minutes) tarnishes to orange–brown. Reflectance data for Commission on Ore Mineralogy (COM) wavelengths in air are [λ (nm), R (%)]: 470, 30.4; 546, 30.3; 589, 30.3; and 650, 28.7. The chemical formula of the samples studied, recalculated on the basis of ΣMe = 16 atoms per formula unit, is: (Ag3.28Cu2.72)Ʃ6.00[Cu4(Cd1.68Fe0.27Zn0.16)]Ʃ6.11(Sb3.71As0.15)Ʃ3.86S12.79. Argentotetrahedrite-(Cd) is cubic, I$bar{4}$3m, with a = 10.65(2) Å, V = 1208(4) Å3 and Z = 2. Argentotetrahedrite-(Cd) is isotypic with other members of the tetrahedrite group. The structural relationship between argentotetrahedrite-(Cd) and other members of the freibergite series are discussed and previous findings of this species are briefly reviewed.
摘要银四面体-（Cd），Ag6（Cu4Cd2）Sb4S13，已被国际矿物学协会新矿物、命名和分类委员会批准为一种新矿物，使用了斯洛伐克共和国Rudno nad Hronom的样品。它以大小达30μm的二面体颗粒出现，颜色从钢灰色到黑色，具有金属光泽，与绿柱石和其他四面体族矿物[银四面体-（Zn）和四面体-（Zn。银四面体-（Cd）是各向同性的，颜色为灰色，呈乳白色，并迅速（数十分钟）变色为橙色-棕色。矿石矿物学委员会（COM）波长在空气中的反射率数据为[λ（nm），R（%）]:470，30.4；54630.3；58930.3；以及650、28.7。所研究样品的化学式，根据∑Me=每个化学式单位16个原子重新计算，为：（Ag3.28Cu2.72）Ʃ6.00[Cu4（Cd1.68Fe0.27Zn0.16）]4256.11（Sb3.71As0.15）4253.86S12.79。银四面体-（Cd）为立方，I$bar｛4｝$3m，a=10.65（2）Å，V=1208（4）Å3，Z=2。银四面体-（Cd）与四面体群的其他成员是同型的。本文讨论了银四面体-（Cd）与氟绿柱石系列其他成员的结构关系，并简要评述了该物种的研究进展。
{"title":"Argentotetrahedrite-(Cd), Ag6(Cu4Cd2)Sb4S13, a new member of the tetrahedrite group from Rudno nad Hronom, Slovakia.","authors":"T. Mikuš, Jozef Vlasáč, J. Majzlan, J. Sejkora, G. Steciuk, J. Plášil, C. Rößler, Christian Matthes","doi":"10.1180/mgm.2022.138","DOIUrl":"https://doi.org/10.1180/mgm.2022.138","url":null,"abstract":"Abstract Argentotetrahedrite-(Cd), Ag6(Cu4Cd2)Sb4S13, has been approved as a new mineral species by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association using samples from Rudno nad Hronom, Slovak Republic. It occurs as anhedral grains up to 30 μm in size, steel-grey to black in colour, with a metallic lustre, in association with greenockite and other tetrahedrite-group minerals [argentotetrahedrite-(Zn) and tetrahedrite-(Zn)], earlier base-metal minerals, Ag sulfides and sulfosalts (acanthite, pyrargyrite and polybasite) and later galena. Argentotetrahedrite-(Cd) is isotropic, grey in colour, with a creamy tint and rapidly (tens of minutes) tarnishes to orange–brown. Reflectance data for Commission on Ore Mineralogy (COM) wavelengths in air are [λ (nm), R (%)]: 470, 30.4; 546, 30.3; 589, 30.3; and 650, 28.7. The chemical formula of the samples studied, recalculated on the basis of ΣMe = 16 atoms per formula unit, is: (Ag3.28Cu2.72)Ʃ6.00[Cu4(Cd1.68Fe0.27Zn0.16)]Ʃ6.11(Sb3.71As0.15)Ʃ3.86S12.79. Argentotetrahedrite-(Cd) is cubic, I$bar{4}$3m, with a = 10.65(2) Å, V = 1208(4) Å3 and Z = 2. Argentotetrahedrite-(Cd) is isotypic with other members of the tetrahedrite group. The structural relationship between argentotetrahedrite-(Cd) and other members of the freibergite series are discussed and previous findings of this species are briefly reviewed.","PeriodicalId":18618,"journal":{"name":"Mineralogical Magazine","volume":"87 1","pages":"262 - 270"},"PeriodicalIF":2.7,"publicationDate":"2022-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46398837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Tolstykh, A. Kasatkin, F. Nestola, A. Vymazalová, A. Agakhanov, G. Palyanova, V. Korolyuk
Abstract Auroselenide, ideally AuSe, is a new mineral from the Gaching ore occurrence of the Maletoyvayam deposit, Kamchatka peninsula, Russia. It occurs as anhedral grains up to 0.05 × 0.02 mm and as intergrowths up to 0.06 mm with maletoyvayamite–tolstykhite-series minerals, enclosed in native gold. Other associated minerals include pyrite, calaverite, fischesserite, gachingite, tetrahedrite-group minerals [stibiogoldfieldite, its As-analogue, tennantite-(Cu) and tetrahedrite-(Zn)], tripuhyite, minerals of the famatinite–luzonite and selenium–tellurium series, paraguanajuatite, petrovskaite, součekite and tiemannite. Auroselenide is bluish-grey, opaque with metallic lustre and grey streak. It is brittle and has an uneven fracture. Dcalc = 9.750 g/cm3. In reflected light, auroselenide is grey with a bluish shade. Bireflectance is very weak. No pleochroism and internal reflections are observed. In crossed polars, it is strongly anisotropic with bluish to brownish rotation tints. The reflectance values for wavelengths recommended by the Commission on Ore Mineralogy of the International Mineralogical Association are (Rmin/Rmax, %): 28.4/31.5 (470 nm), 30.2/33.3 (546 nm), 31.9/34.9 (589 nm) and 34.3/37.3 (650 nm). The principal bands in the Raman spectrum of auroselenide are at 93, 171, 200, 210 and 325 cm–1. The empirical formula calculated on the basis of 2 atoms per formula unit is (Au0.98Ag0.01)Σ0.99(Se0.79S0.17Te0.05)Σ1.01. Auroselenide is monoclinic, space group C2/m, a = 8.319(1), b = 3.616(1), c = 6.276(2) Å, β = 104.54(2)°, V = 182.74(5) Å3 and Z = 4. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 4.015 (54) (200); 3.033 (25) (${bar 1}$11, 002); 2.780 (100) (${bar 2}$02, 111); 2.172 (20) (${bar 3}$11, 310); and 1.811 (25) (${bar 1}$13). Auroselenide is the natural analogue of synthetic β-AuSe. The structural identity between them is confirmed by powder X-ray diffraction and Raman spectroscopy. The mineral is named according to its composition, as a combination of the main elements Au (aurum) and Se (selenium).
{"title":"Auroselenide, AuSe, a new mineral from Maletoyvayam deposit, Kamchatka peninsula, Russia","authors":"N. Tolstykh, A. Kasatkin, F. Nestola, A. Vymazalová, A. Agakhanov, G. Palyanova, V. Korolyuk","doi":"10.1180/mgm.2022.137","DOIUrl":"https://doi.org/10.1180/mgm.2022.137","url":null,"abstract":"Abstract Auroselenide, ideally AuSe, is a new mineral from the Gaching ore occurrence of the Maletoyvayam deposit, Kamchatka peninsula, Russia. It occurs as anhedral grains up to 0.05 × 0.02 mm and as intergrowths up to 0.06 mm with maletoyvayamite–tolstykhite-series minerals, enclosed in native gold. Other associated minerals include pyrite, calaverite, fischesserite, gachingite, tetrahedrite-group minerals [stibiogoldfieldite, its As-analogue, tennantite-(Cu) and tetrahedrite-(Zn)], tripuhyite, minerals of the famatinite–luzonite and selenium–tellurium series, paraguanajuatite, petrovskaite, součekite and tiemannite. Auroselenide is bluish-grey, opaque with metallic lustre and grey streak. It is brittle and has an uneven fracture. Dcalc = 9.750 g/cm3. In reflected light, auroselenide is grey with a bluish shade. Bireflectance is very weak. No pleochroism and internal reflections are observed. In crossed polars, it is strongly anisotropic with bluish to brownish rotation tints. The reflectance values for wavelengths recommended by the Commission on Ore Mineralogy of the International Mineralogical Association are (Rmin/Rmax, %): 28.4/31.5 (470 nm), 30.2/33.3 (546 nm), 31.9/34.9 (589 nm) and 34.3/37.3 (650 nm). The principal bands in the Raman spectrum of auroselenide are at 93, 171, 200, 210 and 325 cm–1. The empirical formula calculated on the basis of 2 atoms per formula unit is (Au0.98Ag0.01)Σ0.99(Se0.79S0.17Te0.05)Σ1.01. Auroselenide is monoclinic, space group C2/m, a = 8.319(1), b = 3.616(1), c = 6.276(2) Å, β = 104.54(2)°, V = 182.74(5) Å3 and Z = 4. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 4.015 (54) (200); 3.033 (25) (${bar 1}$11, 002); 2.780 (100) (${bar 2}$02, 111); 2.172 (20) (${bar 3}$11, 310); and 1.811 (25) (${bar 1}$13). Auroselenide is the natural analogue of synthetic β-AuSe. The structural identity between them is confirmed by powder X-ray diffraction and Raman spectroscopy. The mineral is named according to its composition, as a combination of the main elements Au (aurum) and Se (selenium).","PeriodicalId":18618,"journal":{"name":"Mineralogical Magazine","volume":"87 1","pages":"284 - 291"},"PeriodicalIF":2.7,"publicationDate":"2022-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41535948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Lykova, R. Rowe, G. Poirier, H. Friis, K. Helwig
Abstract The new mineral bounahasite, Cu+Cu2+2(OH)3Cl2, was found in the oxidation zone of the Bou Nahas Mine, Morocco. It forms pseudo-hexagonal plates up to 3 × 30 × 40 μm in size combined in loose clusters with native copper and paratacamite. The mineral is green with vitreous lustre. The cleavage is parallel to {110}, perfect. Dcalc is 3.90 g/cm3. The infrared spectrum is reported. The composition (wt.%) is Cu2O 23.26, CuO 51.72, Cl 23.36, H2O 8.71, O = Cl2 –5.27, total 101.78. The empirical formula calculated on the basis of 3 Cu atoms per formula unit is: Cu+Cu2+2(OH)2.97Cl2.03. The mineral is monoclinic, P21/n, a = 8.5925(1), b = 6.4189(1), c = 10.4118(2) Å, β = 111.804(2)°, V = 533.17(2) Å3 and Z = 4. The strongest reflections of the powder X-ray diffraction pattern [d,Å(I)(hkl)] are: 7.71(70)($bar{1}$01), 5.34(22)(011), 3.856(100)(012, $bar{2}$02), 2.673(36)(022), 2.665 (30)(103) and 2.350 (71)($bar{1}$23, 301, $bar{2}$14). The crystal structure, refined from single-crystal X-ray diffraction data (R1 = 0.028), is based on two alternating sheets coplanar to (110): one consists of alternating edge-sharing Cu2+(OH)6 octahedra and two Cu2+(OH)4Cl2 octahedra, whereas the other one is based on Cu+Cl4 tetrahedra forming edge-sharing Cu+2Cl6 dimers.
{"title":"Bounahasite, Cu+Cu2+2(OH)3Cl2, a new mineral from the Bou Nahas Mine, Morocco","authors":"I. Lykova, R. Rowe, G. Poirier, H. Friis, K. Helwig","doi":"10.1180/mgm.2022.133","DOIUrl":"https://doi.org/10.1180/mgm.2022.133","url":null,"abstract":"Abstract The new mineral bounahasite, Cu+Cu2+2(OH)3Cl2, was found in the oxidation zone of the Bou Nahas Mine, Morocco. It forms pseudo-hexagonal plates up to 3 × 30 × 40 μm in size combined in loose clusters with native copper and paratacamite. The mineral is green with vitreous lustre. The cleavage is parallel to {110}, perfect. Dcalc is 3.90 g/cm3. The infrared spectrum is reported. The composition (wt.%) is Cu2O 23.26, CuO 51.72, Cl 23.36, H2O 8.71, O = Cl2 –5.27, total 101.78. The empirical formula calculated on the basis of 3 Cu atoms per formula unit is: Cu+Cu2+2(OH)2.97Cl2.03. The mineral is monoclinic, P21/n, a = 8.5925(1), b = 6.4189(1), c = 10.4118(2) Å, β = 111.804(2)°, V = 533.17(2) Å3 and Z = 4. The strongest reflections of the powder X-ray diffraction pattern [d,Å(I)(hkl)] are: 7.71(70)($bar{1}$01), 5.34(22)(011), 3.856(100)(012, $bar{2}$02), 2.673(36)(022), 2.665 (30)(103) and 2.350 (71)($bar{1}$23, 301, $bar{2}$14). The crystal structure, refined from single-crystal X-ray diffraction data (R1 = 0.028), is based on two alternating sheets coplanar to (110): one consists of alternating edge-sharing Cu2+(OH)6 octahedra and two Cu2+(OH)4Cl2 octahedra, whereas the other one is based on Cu+Cl4 tetrahedra forming edge-sharing Cu+2Cl6 dimers.","PeriodicalId":18618,"journal":{"name":"Mineralogical Magazine","volume":"87 1","pages":"218 - 224"},"PeriodicalIF":2.7,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46652149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Chukanov, S. Aksenov, O. Kazheva, I. Pekov, D. Varlamov, M. Vigasina, D. I. Belakovskiy, S. A. Vozchikova, S. Britvin
Abstract The new eudialyte-group mineral selsurtite, ideally (H3O)12Na3(Ca3Mn3)(Na2Fe)Zr3□Si[Si24O69(OH)3](OH)Cl⋅H2O, was discovered in metasomatic peralkaline rock from the Flora mountain, northern spur of the Selsurt mountain, Lovozero alkaline massif, Kola Peninsula, Russia. The associated minerals are aegirine, albite and orthoclase, as well as accessory lorenzenite, calciomurmanite, natrolite, lamprophyllite and sergevanite. Selsurtite occurs as brownish-red to reddish-orange, equant or flattened on (0001) crystals up to 2 mm across and elongate crystals up to 3 cm long. The main crystal forms are {0001}, {11$bar{2}$0}, and {10$bar{1}$1}. Selsurtite is brittle, with the Mohs’ hardness of 5. No cleavage is observed. Parting is distinct on (001). D(meas) = 2.73(2) and D(calc) = 2.722 g⋅cm–3. Selsurtite is optically uniaxial (–), with ω = 1.598(2) and ɛ = 1.595(2). The chemical composition is (wt.%, electron microprobe): Na2O 6.48, K2O 0.27, MgO 0.10, CaO 6.83, MnO 4.73, FeO 1.18, SrO 1.88, La2O3 0.57, Ce2O3 1.07, Pr2O3 0.20, Nd2O3 0.44, Al2O3 0.29, SiO2 50.81, ZrO2 13.50, HfO2 0.45, TiO2 0.61, Nb2О5 1.10, Cl 1.01, SO3 0.29, H2O 8.10, –O≡Cl –0.23, total 99.68. The empirical formula is H25.94Na6.03K0.16Mg0.07Ca3.51Sr0.52Ce0.19La0.10Nd0.08Pr0.03Mn1.91Fe0.47Ti0.22Zr3.16Hf0.06Nb0.24Si24.40Al0.16S0.10Cl0.82O79.13. The crystal structure was determined using single-crystal X-ray diffraction data and refined to R = 0.0484. Selsurtite is trigonal, space group R3, with a = 14.1475(7) Å, c = 30.3609(12) Å, V = 5262.65(7) Å3 and Z = 3. Infrared and Raman spectra show that hydronium cations are involved in very strong hydrogen bonds and form Zundel- and Eigen-like complexes. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %)(hkl)] are: 11.38 (56)(101), 7.08 (59)(110), 5.69 (36)(202), 4.318 (72)(205), 3.793 (36)(303), 3.544 (72)(027, 220, 009), 2.970 (100)(315) and 2.844 (100)(404). The mineral is named after the discovery locality.
{"title":"Selsurtite, (H3O)12Na3(Ca3Mn3)(Na2Fe)Zr3□Si[Si24O69(OH)3](OH)Cl⋅H2O, a new eudialyte-group mineral from the Lovozero alkaline massif, Kola Peninsula, Russia","authors":"N. Chukanov, S. Aksenov, O. Kazheva, I. Pekov, D. Varlamov, M. Vigasina, D. I. Belakovskiy, S. A. Vozchikova, S. Britvin","doi":"10.1180/mgm.2022.136","DOIUrl":"https://doi.org/10.1180/mgm.2022.136","url":null,"abstract":"Abstract The new eudialyte-group mineral selsurtite, ideally (H3O)12Na3(Ca3Mn3)(Na2Fe)Zr3□Si[Si24O69(OH)3](OH)Cl⋅H2O, was discovered in metasomatic peralkaline rock from the Flora mountain, northern spur of the Selsurt mountain, Lovozero alkaline massif, Kola Peninsula, Russia. The associated minerals are aegirine, albite and orthoclase, as well as accessory lorenzenite, calciomurmanite, natrolite, lamprophyllite and sergevanite. Selsurtite occurs as brownish-red to reddish-orange, equant or flattened on (0001) crystals up to 2 mm across and elongate crystals up to 3 cm long. The main crystal forms are {0001}, {11$bar{2}$0}, and {10$bar{1}$1}. Selsurtite is brittle, with the Mohs’ hardness of 5. No cleavage is observed. Parting is distinct on (001). D(meas) = 2.73(2) and D(calc) = 2.722 g⋅cm–3. Selsurtite is optically uniaxial (–), with ω = 1.598(2) and ɛ = 1.595(2). The chemical composition is (wt.%, electron microprobe): Na2O 6.48, K2O 0.27, MgO 0.10, CaO 6.83, MnO 4.73, FeO 1.18, SrO 1.88, La2O3 0.57, Ce2O3 1.07, Pr2O3 0.20, Nd2O3 0.44, Al2O3 0.29, SiO2 50.81, ZrO2 13.50, HfO2 0.45, TiO2 0.61, Nb2О5 1.10, Cl 1.01, SO3 0.29, H2O 8.10, –O≡Cl –0.23, total 99.68. The empirical formula is H25.94Na6.03K0.16Mg0.07Ca3.51Sr0.52Ce0.19La0.10Nd0.08Pr0.03Mn1.91Fe0.47Ti0.22Zr3.16Hf0.06Nb0.24Si24.40Al0.16S0.10Cl0.82O79.13. The crystal structure was determined using single-crystal X-ray diffraction data and refined to R = 0.0484. Selsurtite is trigonal, space group R3, with a = 14.1475(7) Å, c = 30.3609(12) Å, V = 5262.65(7) Å3 and Z = 3. Infrared and Raman spectra show that hydronium cations are involved in very strong hydrogen bonds and form Zundel- and Eigen-like complexes. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %)(hkl)] are: 11.38 (56)(101), 7.08 (59)(110), 5.69 (36)(202), 4.318 (72)(205), 3.793 (36)(303), 3.544 (72)(027, 220, 009), 2.970 (100)(315) and 2.844 (100)(404). The mineral is named after the discovery locality.","PeriodicalId":18618,"journal":{"name":"Mineralogical Magazine","volume":"87 1","pages":"241 - 251"},"PeriodicalIF":2.7,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43251829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Carbonatites are igneous carbonate rocks. They are the main source of the rare earth elements (REE) that are essential in low carbon and high technology applications. Exploration targeting and mine planning would both benefit from a better understanding of the processes that create the almost ubiquitous alkaline and REE-bearing metasomatic aureoles in the surrounding country rocks. Using scanning electron microscopy and whole-rock geochemistry, we investigated the composition and mineralogy of the fenite aureoles developed around the REE-poor Chilwa Island carbonatite and the REE-rich Kangankunde carbonatite, which intrude similar country rocks in the Chilwa Alkaline Province of Southern Malawi. Although common characteristics and trends in their mineralogy and composition may be typical of fenites in general, there are significant differences in their petrography and petrogenesis. For example, the mineralogically diverse breccia at Kangankunde contrasts with the intensely altered potassic breccia of Chilwa Island. This might be caused by differing sequences of fluids expelled from the carbonatites into the aureoles. The main REE-bearing mineral in fenite is different at each complex, and reflects the characteristic REE-bearing mineral of the main carbonatite: fluorapatite at Chilwa Island; and monazite at Kangankunde. Each fenite has distinctive mineral assemblages, in which the relative abundance of the REE-bearing minerals appears to be determined by the mineralogy of their respective host carbonatites. At both localities, the REE minerals in fenite are less enriched in lanthanum and cerium than their equivalents in carbonatite, a characteristic that we attribute to REE fractionation within fluids in the aureole. Identifying the mineral assemblages present in fenite and understanding the sequence of alkaline and mineralising fluid events could therefore be useful in predicting whether a fenite is associated with a REE-rich carbonatite. Detailed studies of other aureoles would be required to assess the reliability of these characteristics.
{"title":"A comparison of the fenites at the Chilwa Island and Kangankunde carbonatite complexes, Malawi","authors":"E. Dowman, F. Wall, P. Treloar","doi":"10.1180/mgm.2022.134","DOIUrl":"https://doi.org/10.1180/mgm.2022.134","url":null,"abstract":"Abstract Carbonatites are igneous carbonate rocks. They are the main source of the rare earth elements (REE) that are essential in low carbon and high technology applications. Exploration targeting and mine planning would both benefit from a better understanding of the processes that create the almost ubiquitous alkaline and REE-bearing metasomatic aureoles in the surrounding country rocks. Using scanning electron microscopy and whole-rock geochemistry, we investigated the composition and mineralogy of the fenite aureoles developed around the REE-poor Chilwa Island carbonatite and the REE-rich Kangankunde carbonatite, which intrude similar country rocks in the Chilwa Alkaline Province of Southern Malawi. Although common characteristics and trends in their mineralogy and composition may be typical of fenites in general, there are significant differences in their petrography and petrogenesis. For example, the mineralogically diverse breccia at Kangankunde contrasts with the intensely altered potassic breccia of Chilwa Island. This might be caused by differing sequences of fluids expelled from the carbonatites into the aureoles. The main REE-bearing mineral in fenite is different at each complex, and reflects the characteristic REE-bearing mineral of the main carbonatite: fluorapatite at Chilwa Island; and monazite at Kangankunde. Each fenite has distinctive mineral assemblages, in which the relative abundance of the REE-bearing minerals appears to be determined by the mineralogy of their respective host carbonatites. At both localities, the REE minerals in fenite are less enriched in lanthanum and cerium than their equivalents in carbonatite, a characteristic that we attribute to REE fractionation within fluids in the aureole. Identifying the mineral assemblages present in fenite and understanding the sequence of alkaline and mineralising fluid events could therefore be useful in predicting whether a fenite is associated with a REE-rich carbonatite. Detailed studies of other aureoles would be required to assess the reliability of these characteristics.","PeriodicalId":18618,"journal":{"name":"Mineralogical Magazine","volume":"87 1","pages":"300 - 323"},"PeriodicalIF":2.7,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43419614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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