scholarly journals Eliopoulosite, V7S8, A New Sulfide from the Podiform Chromitite of the Othrys Ophiolite, Greece

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 245 ◽  
Author(s):  
Luca Bindi ◽  
Federica Zaccarini ◽  
Paola Bonazzi ◽  
Tassos Grammatikopoulos ◽  
Basilios Tsikouras ◽  
...  
Keyword(s):  
Empirical Formula ◽  
Mineral Exploration ◽  
Polarized Light ◽  
Structural Data ◽  
Ore Deposits ◽  
New Mineral ◽  
International Mineralogical Association ◽  
New Mineral Species ◽  
Geochemical Studies ◽  
Of Greece

The new mineral species, eliopoulosite, V7S8, was discovered in the abandoned chromium mine of Agios Stefanos of the Othrys ophiolite, located in central Greece. The investigated samples consist of massive chromitite hosted in a strongly altered mantle tectonite, and are associated with nickelphosphide, awaruite, tsikourasite, and grammatikopoulosite. Eliopoulosite is brittle and has a metallic luster. In plane-reflected polarized light, it is grayish-brown and shows no internal reflections, bireflectance, and pleochroism. It is weakly anisotropic, with colors varying from light to dark greenish. Reflectance values of mineral in air (Ro, Re’ in %) are: 34.8–35.7 at 470 nm, 38–39 at 546 nm, 40–41.3 at 589 nm, and 42.5–44.2 at 650 nm. Electron-microprobe analyses yielded a mean composition (wt.%) of: S 41.78, V 54.11, Ni 1.71, Fe 1.1, Co 0.67, and Mo 0.66, totali 100.03. On the basis of Σatoms = 15 apfu and taking into account the structural data, the empirical formula of eliopoulosite is (V6.55Ni0.19Fe0.12Co0.07Mo0.04)Σ = 6.97S8.03. The simplified formula is (V, Ni, Fe)7S8 and the ideal formula is V7S8, which corresponds to V 58.16%, S 41.84%, total 100 wt.%. The density, based on the empirical formula and unit-cell volume refined form single-crystal structure XRD data, is 4.545 g·cm−3. The mineral is trigonal, space group P3221, with a = 6.689(3) Å, c = 17.403(6) Å, V = 674.4(5) Å3, Z = 3, and exhibits a twelve-fold superstructure (2a × 2a × 3c) of the NiAs-type subcell with V-atoms octahedrally coordinated by S atoms. The distribution of vacancies is discussed in relation to other pyrrhotite-like compounds. The mineral name is for Dr. Demetrios Eliopoulos (1947–2019), a geoscientist at the Institute of Geology and Mineral Exploration (IGME) of Greece and his widow, Prof. Maria Eliopoulos (nee Economou, 1947), University of Athens, Greece, for their contributions to the knowledge of ore deposits of Greece and to the mineralogical, petrographic, and geochemical studies of ophiolites, including the Othrys complex. The mineral and its name have been approved by the Commission of New Minerals, Nomenclature, and Classification of the International Mineralogical Association (No. 2019-96).

Lucchesiite, CaFe2+3Al6(Si6O18)(BO3)3(OH)3O, a new mineral species of the tourmaline supergroup

2017 ◽  
Vol 81 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Ferdinando Bosi ◽  
Henrik Skogby ◽  
Marco E. Ciriotti ◽  
Petr Gadas ◽  
Milan Novák ◽  
...  
Keyword(s):  
Czech Republic ◽  
Sri Lanka ◽  
Polarized Light ◽  
New Mineral ◽  
Crystal Chemical Analysis ◽  
Calculated Density ◽  
International Mineralogical Association ◽  
Conchoidal Fracture ◽  
New Mineral Species ◽  
Coupled Substitution

AbstractLucchesiite, CaFe32+Al6(Si6O18)(BO3)3(OH)3O, is a new mineral of the tourmaline supergroup. It occurs in the Ratnapura District, Sri Lanka (6°35'N, 80°35'E), most probably from pegmatites and in Mirošov near Strážek, western Moravia, Czech Republic, (49°27'49.38"N, 16°9'54.34"E) in anatectic pegmatite contaminated by host calc-silicate rock. Crystals are black with a vitreous lustre, conchoidal fracture and grey streak. Lucchesiite has a Mohs hardnessof ∼7 and a calculated density of 3.209 g/cm3(Sri Lanka) to 3.243 g/cm3(Czech Republic). In plane-polarized light, lucchesiite is pleochroic (O = very dark brown and E = light brown) and uniaxial (–). Lucchesiite is rhombohedral, space groupR3m,a≈ 16.00 Å,c≈ 7.21 Å,V≈ 1599.9 Å3,Z= 3. The crystal structure of lucchesiite was refined toR1 ≈ 1.5% using ∼2000 unique reflections collected with MoKα X-ray intensity data. Crystal-chemical analysis for the Sri Lanka (holotype) and Czech Republic (cotype) samples resulted in the empirical formulae, respectively:X(Ca0.69Na0.30K0.02)∑1.01Y(Fe1.442+Mg0.72Al0.48Ti0.334+V0.023+Mn0.013+Zn0.01)∑3.00Z(Al4.74Mg1.01Fe0.253+)∑6.00[T(Si5.85Al0.15)∑6.00O18](BO3)3V(OH)3W[O0.69F0.24(OH)0.07]∑1.00andX(Ca0.49Na0.45□0.05K0.01)∑1.00Y(Fe1.142+Fe0.953+Mg0.42Al0.37Mn0.03Ti0.084+Zn0.01)∑3.00Z(Al5.11Fe0.383+Mg0.52)∑6.00[T(Si5.88Al0.12)∑6.00O18](BO3)3V[(OH)2.66O0.34]∑3.00W(O0.94F0.06)∑1.00.Lucchesiite is an oxy-species belonging to the calcic group of the tourmaline supergroup. The closest end-member composition of a valid tourmaline species is that of feruvite, to which lucchesiite is ideally related by the heterovalent coupled substitutionZAl3++O1O2–↔ZMg2++O1(OH)1–. The new mineral was approved by the International Mineralogical Association Commission on New Minerals, Nomenclature and Classification (IMA 2015-043).

scholarly journals Grammatikopoulosite, NiVP, a New Phosphide from the Chromitite of the Othrys Ophiolite, Greece

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 131 ◽  
Author(s):  
Luca Bindi ◽  
Federica Zaccarini ◽  
Elena Ifandi ◽  
Basilios Tsikouras ◽  
Chris Stanley ◽  
...  
Keyword(s):  
Empirical Formula ◽  
Polarized Light ◽  
Orthorhombic Space Group ◽  
Average Composition ◽  
International Mineralogical Association ◽  
Small Crystals ◽  
Podiform Chromitite ◽  
Of Greece ◽  
The Ideal

Grammatikopoulosite, NiVP, is a new phosphide discovered in the podiform chromitite and hosted in the mantle sequence of the Othrys ophiolite complex, central Greece. The studied samples were collected from the abandoned chromium mine of Agios Stefanos. Grammatikopoulosite forms small crystals (from 5 μm up to about 80 μm) and occurs as isolated grains. It is associated with nickelphosphide, awaruite, tsikourasite, and an undetermined V-sulphide. It is brittle and has a metallic luster. In plane-polarized light, it is creamy-yellow, weakly bireflectant, with measurable but not discernible pleochroism and slight anisotropy with indeterminate rotation tints. Internal reflections were not observed. Reflectance values of mineral in air (R1, R2 in %) are: 48.8–50.30 at 470 nm, 50.5–53.5 at 546 nm, 51.7–55.2 at 589 nm, and 53.2–57.1 at 650 nm. Five spot analyses of grammatikopoulosite give the average composition: P 19.90, S 0.41, Ni 21.81, V 20.85, Co 16.46, Mo 16.39, Fe 3.83, and Si 0.14, total 99.79 wt %. The empirical formula of grammatikopoulosite—based on Σ(V + Ni + Co + Mo + Fe + Si) = 2 apfu, and taking into account the structural results—is (Ni0.57Co0.32Fe0.11)Σ1.00(V0.63Mo0.26Co0.11)Σ1.00(P0.98S0.02)Σ1.00. The simplified formula is (Ni,Co)(V,Mo)P and the ideal formula is NiVP, which corresponds to Ni 41.74%, V 36.23%, P 22.03%, total 100 wt %. The density, calculated on the basis of the empirical formula and single-crystal data, is 7.085 g/cm3. The mineral is orthorhombic, space group Pnma, with a = 5.8893(8), b = 3.5723(4), c = 6.8146(9) Å, V = 143.37(3) Å3, and Z = 4. The mineral and its name have been approved by the Commission of New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA 2019-090). The mineral honors Tassos Grammatikopoulos, geoscientist at the SGS Canada Inc., for his contribution to the economic mineralogy and mineral deposits of Greece.

scholarly journals Arsenotučekite, Ni18Sb3AsS16, a new mineral from the Tsangli chromitites, Othrys ophiolite, Greece

2020 ◽  
Vol 114 (5) ◽  
pp. 435-442
Author(s):  
Federica Zaccarini ◽  
Luca Bindi ◽  
Basilios Tsikouras ◽  
Tassos Grammatikopoulos ◽  
Christopher J. Stanley ◽  
...  
Keyword(s):  
Mass Density ◽  
Polarized Light ◽  
Mantle Peridotite ◽  
New Mineral ◽  
Forming Process ◽  
International Mineralogical Association ◽  
Magmatic Sulfides ◽  
New Mineral Species ◽  
Reflected Light

Abstract Arsenotučekite, Ni18Sb3AsS16, is a new mineral discovered in the abandoned chromium mine of Tsangli, located in the eastern portion of the Othrys ophiolite complex, central Greece. Tsangli is one of the largest chromite deposit at which chromite was mined since 1870. The Tsangli chromitite occurs as lenticular and irregular bodies. The studied chromitites are hosted in a strongly serpentinized mantle peridotite. Arsenotučekite forms anhedral to subhedral grains that vary in size between 5 μm up to 100 μm, and occurs as single phase grains or is associated with pentlandite, breithauptite, gersdorffite and chlorite. It is brittle and has a metallic luster. In plane-polarized light, it is creamy-yellow, the bireflectance is barely perceptible and the pleochroism is weak. In crossed polarized reflected light, the anisotropic rotation tints vary from pale blue to brown. Internal reflections were not observed. Reflectance values of arsenotučekite in air (Ro, Re′ in %) are: 41.8–46.4 at 470 nm, 47.2–50.6 at 546 nm, 49.4–52.3 at 589 nm, and 51.3–53.2 at 650 nm. The empirical formula of arsenotučekite, based on 38 atoms per formula unit, and according to the structural results, is (Ni16.19Co1.01Fe0.83)Σ18.03Sb3(As0.67Sb0.32)Σ0.99S15.98. The mass density is 6.477 g·cm−3. The simplified chemical formula is (Ni,Co,Fe)18Sb3(As,Sb)S16. The mineral is tetragonal and belongs to space group I4/mmm, with a = 9.7856(3) Å, c = 10.7582(6) Å, V = 1030.2(6) Å3 and Z = 2. The structure is layered (stacking along the c-axis) and is dominated by three different Ni-coordination polyhedral, one octahedral and two cubic. The arsenotučekite structure can be considered as a superstructure of tučekite resulting from the ordering of Sb and As. The name of the new mineral species indicates the As-dominant of tučekite. Arsenotučekite occurs as rims partly replacing pentlandite and irregularly developed grains. Furthermore, it is locally associated with chlorite. These observations suggest that it was likely precipitated at relatively low temperatures during: 1) the late hydrothermal stages of the ore-forming process by reaction of Sb- and As-bearing solutions with magmatic sulfides such as pentlandite, or 2) during the serpentinization of the host peridotite. The mineral and its name have been approved by the Commission of New Minerals, Nomenclature, and Classification of the International Mineralogical Association (number 2019–135).

scholarly journals MINERAIS DE COLEÇÃO: CIÊNCIA, ESTÉTICA E MERCADO

2013 ◽  
Author(s):  
Luiz Alberto Dias Menezes Filho ◽  
Mario Luiz de Sá Carneiro Chaves
Keyword(s):  
Mineral Exploration ◽  
Ore Deposits ◽  
Mineral Species ◽  
New Mineral ◽  
Market Incentives ◽  
New Mineral Species ◽  
The World ◽  
Industrial Mining

algumas centenas no Brasil. O comércio desses minerais movimenta por ano algumas dezenas de milhões dedólares, proporcionando renda e condições de subsistência a regiões pobres do Brasil e de outros países. Essemercado também incentiva a produção em pequenos depósitos minerais e isso tem permitido a descoberta e apreservação de novas espécies minerais que de outra forma permaneceriam desconhecidas. O Brasil é um dosmaiores produtores mundiais de minerais para coleção, entretanto quase que exclusivamente provenientes deatividades de garimpagem. O riquíssimo patrimônio mineralógico contido em jazidas de grandes mineraçõesindustriais tem sido perdido, devido ao desinteresse de tais empresas e seus corpos técnicos em estudar amineralogia dessas jazidas.Palavras-chave: minerais, coleções, exploração mineral. ABSTRACT: The hobby of mineral collecting has millions of adepts all over the world, but only few hundreds in Brazil.The trade of these minerals amount annually some tens of millions of dollars, providing monetary incentiveto poor regions in Brazil and in other countries. Such market incentives the exploitation of small mineraldeposits and has allowed the discovery and preservation of new mineral species. Brazil is a major producerof minerals for collections, however mostly from the small “garimpo’s” services. The very rich mineralogicalpatrimony from the ore deposits subject to industrial mining has been lost due the lack of interest from thebig companies and their technical staffs to study the mineralogy of these deposits.Keywords: minerals, collections, mineral exploration.

Meieranite, Na2Sr3MgSi6O17, a New Mineral from the Wessels Mine, Kalahari Manganese Fields, South Africa

2019 ◽  
Vol 57 (4) ◽  
pp. 457-466 ◽  
Author(s):  
Hexiong Yang ◽  
Xiangping Gu ◽  
Robert T. Downs ◽  
Stanley H. Evans ◽  
Jaco J. Van Nieuwenhuizen ◽  
...  
Keyword(s):  
South Africa ◽  
Empirical Formula ◽  
Microprobe Analysis ◽  
New Mineral ◽  
Cell Parameters ◽  
New Mineral Species ◽  
General Chemical ◽  
Northern Cape ◽  
Coupled Substitution ◽  
Mohs Hardness

Abstract A new mineral species, meieranite, ideally Na2Sr3MgSi6O17, has been found in the Wessels mine, Kalahari Manganese Fields, Northern Cape Province, South Africa. It occurs in isolated aggregates embedded in a matrix mainly of sugilite, along with minor aegirine and pectolite. Crystals of meieranite are up to 0.5 × 0.5 × 0.4 mm in size. No twinning is observed. The mineral is light blue to blue in transmitted and under incident lights, transparent with white streak, and has vitreous luster. It is brittle and has a Mohs hardness of 5.5; cleavage is good on {010} and no parting was observed. The measured and calculated densities are 3.41(3) and 3.410 g/cm3, respectively. Optically, meieranite is biaxial (–), with α = 1.610(1), β = 1.623(1), γ = 1.630(1) (white light), 2V (meas.) = 70(1)°, 2V (calc.) = 72°. The calculated compatibility index based on the empirical formula is –0.007 (superior). An electron microprobe analysis yields an empirical formula (based on 17 O apfu) of Na1.96(Sr2.91Ba0.03Ca0.03Pb0.02)Σ2.99(Mg0.62Mn0.28Co0.07Fe0.01)Σ0.98Si6.03O17, which can be simplified to Na2Sr3MgSi6O17. Meieranite is orthorhombic, with space group P21nb and unit-cell parameters a 7.9380(2), b 10.4923(3), c 18.2560(6) Å, and V 1520.50(8) Å3. Its crystal structure is characterized by two kinds of layers that alternate along [010]: layers of corner-sharing SiO4 and M2+O4 tetrahedra (M2+ = Mg, Mn, Co, Fe) and layers of NaO6 and SrO8 polyhedra. The tetrahedral layers consist of eight-, five-, and four-membered rings and are composed of [Si6O17] ribbons (parallel to [101]) linked together by MO4 tetrahedra. Most remarkably, the structure of meieranite is topologically identical to that of the nordite group of minerals, which has the general chemical formula Na3SrR3+M2+Si6O17, where R = Ce and La and M = Zn, Fe, and Mn. Accordingly, chemically, meieranite may be obtained through the coupled substitution of 2Sr2+ for (Na+ + R3+) in nordite.

Barikaite, Pb10Ag3(Sb8As11)Σ19S40, a new member of the sartorite homologous series

2013 ◽  
Vol 77 (7) ◽  
pp. 3039-3046 ◽  
Author(s):  
D. Topa ◽  
E. Makovicky ◽  
H. Tajedin ◽  
H. Putz ◽  
G. Zagler
Keyword(s):  
Homologous Series ◽  
Empirical Formula ◽  
Mean Value ◽  
Crystal Structure Analysis ◽  
New Mineral ◽  
Calculated Density ◽  
Cell Parameters ◽  
New Mineral Species ◽  
Reflected Light ◽  
Mohs Hardness

AbstractBarikaite, ideally Pb10Ag3(Sb8As11)Σ19S40, is a new mineral species from the Barika Au-Ag deposit, Azarbaijan Province, western Iran. It was formed in fractures developed in silica bands situated in massive banded pyrite and baryte ores. These fractures house veinlets that contain a number of Ag-As-Sb-Pb-rich sulfosalts, tetrahedrite-tennantite, realgar, pyrite and electrum. Barikaite appears as inclusions in guettardite. The mineral is opaque, greyish black with a metallic lustre; it is brittle without any discernible cleavage. In reflected light barikaite is greyish white, pleochroism is distinct, white to dark grey. Internal reflections are absent. In crossed polars, anisotropism is distinct with rotation tints in shades of grey. The reflectance data (%, in air) are: 37.0, 39.3 at 470 nm, 34.1, 36.9 at 546 nm, 33.1, 36.2 at 589 nm and 31.3, 34.1 at 650 nm. The Mohs hardness is 3–3½, microhardness VHN50 exhibits the range 192 – 212, with a mean value of 200 kg mm–2. The average results of five electron-microprobe analyses in a grain are (in wt.%): Pb 35.77(33), Ag 5.8(1), Tl 0.15(08), Sb 18.33(09), As 15.64(16), S 24.00(15), total 99.69(10) wt.%, corresponding to Pb9.31Ag2.90Tl0.04(Sb8.12As11.26)Σ19.36S40.37 (on the basis of 32Me + 40S = 72 a.p.f.u.). The simplified formula, Pb10Ag3(Sb8As11)Σ19S40, is in accordance with the results of a crystal-structure analysis, and requires Pb 37.89, Ag 5.91, Sb 17.79, As 15.05 and S 23.42 (wt.%). The variation of chemical composition is minor, the empirical formula ranging from Pb10.39Ag2.32Tl0.02Sb7.52As11.27S40.49 to Pb9.24Ag2.93Tl0.04Sb8.13As11.35S40.31. Barikaite has monoclinic symmetry, space group P21/n and unit-cell parameters a 8.5325(7) Å, b 8.0749(7) Å, c 24.828(2) Å, and b 99.077(6)o, Z = 1. Calculated density for the empirical formula is 5.34 (g cm–3). The strongest eight lines in the (calculated) powder-diffraction pattern [d in Å(I)(hkl)] are: 3.835(63)(022), 3.646(100)(016), 3.441(60)(212), 3.408(62)(14), 2.972(66)(16), 2.769(91)(222), 2.752(78)(24) and 2.133(54)(402). Barikaite is the N = 4 member of the sartorite homologous series with a near-equal role of As and Sb, which have an ordered distribution pattern in the structure. It is a close homeotype of rathite and more distantly related to dufrénoysite (both distinct, pure arsenian N = 4 members) and it completes the spectrum of Sb-rich members of the sartorite homologous series. The new mineral and its name have been approved by the IMA-CNMNC (IMA 2012-055).

scholarly journals MINERAIS RECENTEMENTE DESCRITOS NO BRASIL: A PARTICIPAÇÃO DO CENTRO DE PESQUISA PROF. MANOEL TEIXEIRA DA COSTA - CPMTC, INSTITUTO DE GEOCIÊNCIAS (UFMG)

2018 ◽  
Author(s):  
Mario Luiz de Sá Carneiro Chaves ◽  
Antônio Wilson Romano ◽  
Luiz Alberto Dias Menezes Filho
Keyword(s):  
Minas Gerais ◽  
New Mineral ◽  
Mountain Range ◽  
International Mineralogical Association ◽  
Mineralogical Association ◽  
New Mineral Species ◽  
Eastern Brazil ◽  
Minas Gerais State ◽  
Mining Projects ◽  
Phd Thesis

Embora o potencial mineral do Brasil seja imenso e, por conseguinte, a possibilidade de encontro de novas espécies minerais nos empreendimentos minerários seja naturalmente alta, até 2010 somente 51 descobertas haviam sido verificadas no país. Entretanto, nos últimos sete anos, através de um projeto de Tese de Doutoramento realizado no Programa de Pós-Graduação em Geologia do IGC/UFMG, esta situação procurou ser mudada. Com ênfase em dois dos principais ambientes geológicos do Estado de Minas Gerais e adjacências, a Província Pegmatítica Oriental do Brasil e a Serra do Espinhaço, estudos foram conduzidos visando especificamente o encontro de novos minerais. Destacam-se os resultados extremamenete satisfatórios; nesses anos foram descobertos oito minerais, o que representa média de 1,3 mineral/ano, contrastando com os inexpressivos 0,2 mineral/ano verificados desde 1789 (ano em que o crisoberilo foi descrito). Os novos minerais são, incluindo seus códigos de identificação na International Mineralogical Association (IMA): carlosbarbosaíta [(UO2)2Nb2O6(OH)2.2H2O], IMA 2010-047; pauloabibita [NaNbO3], IMA 2012-090; cesarferreiraíta [Fe2+Fe3+2(AsO4)2(OH)2.8H2O], IMA 2012-099; correianevesita [Fe2+Mn2+2(PO4)2.3H2O], IMA 2013-007; almeidaíta [Pb(Mn,Y)Zn2(Ti,Fe3+)18O36(O,OH)2], IMA 2013-020; wilancookita [(Ba,K,Na)8(Ba,Li,[])6Be24P24O96.3H2O], IMA 2015-034; parisita-(La) [CaLa2(CO3)3F2], IMA 2016-031; e brandãoita [BeAl2(PO4)2(OH)2(H2O)4], IMA 2016-071a. Este foi o primeiro programa de pesquisa desenvolvido no país voltado especialmente para a descoberta de novos minerais, tendo alcançado pleno êxito.Palavras Chave: Novos minerais, Centro de Pesquisa Prof. Manoel Teixeira da Costa, (IGC-UFMG), BrasilAbstract:RECENT MINERALS DESCRIBED IN BRAZIL: PARTICIPATION OF THE CENTRO DE PESQUISA PROF. MANOEL TEIXEIRA DA COSTA - CPMTC, GEOSCIENCES INSTITUTE (UFMG). Although the mineral potential of Brazil is immense and, consequently, the possibility of finding new mineral species in mining projects is obviously high, until 2010 only 51 discoveries had been verified in this country. However, in the last seven years, through a PhD Thesis project carried at the Postgraduate in Geology Program of the IGC/UFMG, this situation has been modified. With emphasis on two of the main geological environments of Minas Gerais State and surrounding regions, the Eastern Brazil Pegmatite Province and the Espinhaço Mountain Range, studies were conducted specifically aimed at finding new minerals. The results are extremely satisfactory; in those years eight minerals were discovered, representing an average of 1.3 mineral/year, contrasting with the inexpressive 0.2 mineral/year verified since 1789 (year of chrysoberyl description). The new minerals are, including their identification codes in the International Mineralogical Association (IMA): carlosbarbosaite [(UO2)2Nb2O6(OH)2.2H2O], IMA 2010-047; pauloabibite [NaNbO3], IMA 2012-090; cesarferreiraita [Fe2+Fe3+2(AsO4)2(OH)2.8H2O], IMA 2012-099; correianevesite [Fe2+Mn2+2(PO4)2.3H2O], IMA 2013-007; almeidaite [Pb(Mn,Y)Zn2(Ti,Fe3+)18O36(O,OH)2], IMA 2013-020; wilancookite [(Ba,K,Na)8(Ba,Li,[])6Be24P24O96.3H2O], IMA 2015-034; parisite-(La) [CaLa2(CO3)3F2], IMA 2016-031; and brandãoite [BeAl2(PO4)2(OH)2(H2O)4], IMA 2016-071a. This was the first research program developed in the country focused especially on the discovery of new minerals, reaching full success.Keywords: New minerals, Prof. Manoel Teixeira da Costa Research Center (IGC-UFMG), Brazil. 

Viteite, Pd5InAs, a new mineral from the Monchetundra layered intrusion, Kola Peninsula, Russia

2020 ◽  
Vol 58 (3) ◽  
pp. 395-402
Author(s):  
A. Vymazalová ◽  
F. Laufek ◽  
T.L. Grokhovskaya ◽  
C.J. Stanley
Keyword(s):  
Kola Peninsula ◽  
Empirical Formula ◽  
Polarized Light ◽  
Layered Intrusion ◽  
Structure Type ◽  
New Mineral ◽  
Synthetic Analogue ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygenated Compounds

ABSTRACT Viteite, Pd5InAs, is a new mineral discovered in the Monchetundra layered intrusion, Kola Peninsula, Russia. It forms euhedral grains about 0.5 to 10 μm in size intergrown with irarsite (IrAsS), hollingworthite (RhAsS), zvyagintsevite (Pd3Pb), Au-Ag alloys, and tulameenite (Pt2CuFe), that are replaced by Pt-Pd-Fe-Cu alloys and Pt-Pd-Fe-Cu oxygenated compounds, all of which are embedded in chalcocite, goethite, and covellite. Viteite is brittle and has a metallic luster. In plane-polarized light, viteite is bright pinkish-white. The mineral is weakly anisotropic with rotation tints blue to pinkish brown; it exhibits no internal reflections. Reflectance values of viteite in air (R1, R2 in %) are 55.7, 54.0 at 470 nm; 59.2, 58.4 at 546 nm; 60.0, 60.4 at 589 nm; and 60.0, 62.6 at 650 nm. Eight electron-microprobe analyses of viteite give an average composition of Pd 71.90, Pt 1.60, Fe 0.98, Cu 0.59, In 11.48, Hg 1.42, Pb 0.40, As 10.70, total 99.07 wt.%, corresponding to the empirical formula (Pd4.92Pt0.06)Σ4.98(In0.73Fe0.12Cu0.07Hg0.05Pb0.01)Σ0.98As1.04 based on 7 atoms; the average of 12 analyses of its synthetic analogue is: Pd 73.72, In 16.37, As 9.80, total 99.90 wt.%, corresponding to Pd5.02In1.03As0.95. The density, calculated on the basis of the empirical formula, is 10.78 g/cm3. The mineral is tetragonal, space group P4/mmm, with a 3.98600(3), c 6.98385(8) Å, V 110.961(2) Å3, and Z = 1. The crystal structure of synthetic Pd5InAs was solved and refined using powder X-ray-diffraction data from synthetic Pd5InAs. Viteite crystallizes with the Pd5TlAs structure type. The strongest lines in the X-ray powder diffraction pattern of synthetic Pd5InAs [d in Å (I) (hkl)] are: 2.3281(45)(003), 2.1932(100)(112), 1.9928(33)(020), 1.2515(17)(115), 1.1857(25)(132). The mineral is named for the Vite river, which flows near the Monchetundra intrusion.

Shannonite, Pb2OCO3, a new mineral from the Grand Reef Mine, Graham County, Arizona, USA

1995 ◽  
Vol 59 (395) ◽  
pp. 305-310 ◽  
Author(s):  
A. C. Roberts ◽  
J. A. R. Stirling ◽  
G. J. C. Carpenter ◽  
A. J. Criddle ◽  
G. C. Jones ◽  
...  
Keyword(s):  
Empirical Formula ◽  
Short Wave ◽  
New Mineral ◽  
Orthorhombic Space Group ◽  
Weak Anisotropy ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
New Mineral Species ◽  
Transmission Electron

AbstractShannonite, ideally Pb2OCO3, is a new mineral species that occurs as mm-sized white porcellanous crusts, associated with fluorite, at the Grand Reef mine, Graham County, Arizona, USA. Other associated minerals are plumbojarosite, hematite, Mn-oxides, muscovite-2M1, quartz, litharge, massicot, hydrocerussite, minium, and unnamed PbCO3·2PbO. Shannonite is orthorhombic, space group P21221 or P212121, with unit-cell parameters (refined from X-ray powder data): a 9.294(3), b 9.000(3), c 5.133(2) Å, V 429.3(3) Å3, a:b:c 1.0327:1:0.5703, Z = 4. The strongest five lines in the X-ray powder pattern [d in Å (I)(hkl)] are: 4.02(40)(111); 3.215(100)(211); 3.181(90)(121); 2.858(40)(130); 2.564(35)(002). The average of eight electron microprobe analyses is PbO 89.9(5), CO2 (by CHN elemental analyser) 9.70, total 99.60 wt.%. With O = 4, the empirical formula is Pb1.91C1.05O4.00. The calculated density for the empirical formula is 7.31 and for the idealized formula is 7.59 g/cm3. In reflected light, shannonite is colourless-grey to white, with ubiquitous white internal reflections (× 16 objectives), weak anisotropy, barely detectable bireflectance, and no evidence of pleochroism. The calculated refractive index (at 590 nm) is 2.09. Measured reflectance values in air and in oil (× 4 objectives) are tabulated. Transmission electron-microscopy studies reveal that individual crystallites range in size from 10–400 nm, are platy, and are anhedral. Physical properties for cryptocrystalline crusts include: white streak; waxy lustre; opaque; nonfluorescent under both long- and short-wave ultraviolet light; uneven fracture; brittle; VHN100 97 (range 93–100); calculated Mohs’ hardness 3–3½. Shannonite is soluble in concentrated HCl and in dilute HNO3 and H2SO4. The mineral name is for David M. Shannon, who helped collect the samples and who initiated this study.

scholarly journals Omariniite, Cu8Fe2ZnGe2S12, the germanium analogue of stannoidite, a new mineral species from Capillitas, Argentina

2017 ◽  
Vol 81 (5) ◽  
pp. 1151-1159 ◽  
Author(s):  
Luca Bindi ◽  
Hubert Putz ◽  
Werner H. Paar ◽  
Christopher J. Stanley
Keyword(s):  
Polarized Light ◽  
New Mineral ◽  
Polished Section ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
New Mineral Species ◽  
Catamarca Province ◽  
Brownish Black ◽  
The University

AbstractOmariniite, ideally Cu8Fe2ZnGe2S12, represents the Ge-analogue of stannoidite and was found in bornite-chalcocite-rich ores near the La Rosario vein of the Capillitas epithermal deposit, Catamarca Province, Argentina. The mineral is associated closely with three other Ge-bearing minerals (putzite, catamarcaite, rarely zincobriartite) and bornite, chalcocite, digenite, covellite, sphalerite, tennantite, luzonite, wittichenite, thalcusite and traces of mawsonite. The width of the seams rarely exceeds 60 μm, their length can attain several 100 μm. The mineral is opaque, orange-brown in polished section, has a metallic lustre and a brownish-black streak. It is brittle, and the fracture is irregular to subconchoidal. Neither cleavage nor parting are observable in the sections. In plane-polarized light omariniite is brownish-orange and has a weak pleochroism. Internal reflections are absent. The mineral is distinctly anisotropic with rotation tints varying between brownish-orange and greenish-brown. The average result of 45 electron-microprobe analyses is Cu 42.18(34), Fe 9.37(26), Zn 5.17(43), In 0.20(6), Ge 11.62(22), S 31.80(20), total 100.34(46) wt.%. The empirical formula, based on Σ(Me + S) = 25, is Cu8.04(Fe2.03In0.02)Σ2.05Zn0.96 Ge1.94S12.01, ideally Cu8+Fe2+Zn2+Ge24+S122-. Omariniite is orthorhombic, space group I222, with unit-cell parameters: a = 10.774(1), b = 5.3921(5), c = 16.085(2) Å, V = 934.5(2) Å3, a:b:c = 1.9981:1:2.9831, Z = 2. X-ray single-crystal studies (R1 = 0.023) revealed the structure to be a sphalerite derivative identical to that of stannoidite. Omariniite is named after Dr. Ricardo Héctor Omarini (1946–2015), Professor at the University of Salta, for his numerous contributions to the geology of Argentina.

Sign in / Sign up

Export Citation Format

Share Document