scholarly journals Tsikourasite, Mo3Ni2P1+x (x < 0.25), a New Phosphide from the Chromitite of the Othrys Ophiolite, Greece

Minerals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 248 ◽  
Author(s):  
Zaccarini ◽  
Bindi ◽  
Ifandi ◽  
Grammatikopoulos ◽  
Stanley ◽  
...  
Keyword(s):  
Empirical Formula ◽  
Polarized Light ◽  
Average Composition ◽  
Synthetic Compound ◽  
Space Group ◽  
International Mineralogical Association ◽  
Mineralogical Association ◽  
Brunei Darussalam ◽  
Podiform Chromitite

Tsikourasite, Mo3Ni2P1+x (x < 0.25), is a new phosphide discovered in a mantle-hosted podiform chromitite collected in the abandoned mine of Agios Stefanos (Othrys ophiolite), Central Greece. It forms tiny grains (from a few μm up to about 80 μm) and occurs as isolated grains or associated with other known minerals such as nickelphosphide and awaruite, and with undetermined minerals such as Ni-allabogdanite or Ni-barringerite and a V-sulphide. Tsikourasite is brittle and has a metallic luster. In plane-polarized light, tsikourasite is white yellow and it shows no bireflectance, anisotropism or pleochroism. Internal reflections were not observed, Reflectance values of tsikourasite in air (R in %) are: 55.7 at 470 nm, 56.8 at 546 nm, 57.5 at 589 nm and 58.5 at 650 nm. Five spot analyses of tsikourasite give the average composition: P 7.97, S 0.67, V 14.13, Fe 14.37, Co 7.59, Ni 23.9, and Mo 44.16, total 99.60 wt%, corresponding to the empirical formula (Mo1.778V1.071Fe0.082Co0.069)Σ3.000(Ni1.572Co0.428)Σ2.000(P0.981S0.079)Σ1.060, on the basis of Σ(Mo +V + Fe + Co + Ni) = 5 apfu and taking into account the structural results. The simplified formula is Mo3Ni2P1+x (x < 0.25). The density, which was calculated based on the empirical formula and single-crystal data, is 9.182 g/cm3. The mineral is cubic, space group F-43m, with a = 10.8215(5) Å and Z = 16. Although tsikourasite is similar in composition to those of monipite (MoNiP), polekhovskyite (MoNiP2), and the synthetic compound MoNiP2, all these phases are hexagonal and not cubic like tsikourasite. It exhibits the same structure as the cubic Mo3Ni2P1.18 compound [space group F-43m, a = 10.846(2) Å] synthesized at 1350 °C. The mineral and its name have been approved by the Commission of New Minerals, Nomenclature and Classification of the International Mineralogical Association (No. 2018-156). The mineral honors Professor Basilios Tsikouras of the Universiti Brunei Darussalam.

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.

Crystal chemistry and nomenclature of rhodonite-group minerals

2019 ◽  
Vol 83 (6) ◽  
pp. 829-835 ◽  
Author(s):  
Nadezhda V. Shchipalkina ◽  
Igor V. Pekov ◽  
Nikita V. Chukanov ◽  
Cristian Biagioni ◽  
Marco Pasero
Keyword(s):  
Crystal Chemistry ◽  
Structural Formula ◽  
Structure Type ◽  
Mineral Species ◽  
Triclinic Space Group ◽  
Space Group ◽  
International Mineralogical Association ◽  
Mineralogical Association ◽  
General Chemical

AbstractThis paper presents the nomenclature of the rhodonite group accepted by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA). An overview of the previous studies of triclinic (space group P$\bar{1}$) pyroxenoids belonging to the rhodonite structure type, with a focus on their crystal chemistry, is given. These minerals have the general structural formula VIIM(5)VIM(1)VIM(2)VIM(3)VIM(4)[Si5O15]. The following dominant cations at the M sites are known at present: M(5) = Ca or Mn2+, M(1–3) = Mn2+; and M(4) = Mn2+ or Fe2+. In accordance with the nomenclature, the rhodonite group consists of three IMA-approved mineral species having the following the general chemical formulae: M(5)AM(1–3)B3M(4)C[Si5O15], where A = Ca or Mn2+; B = Mn2+; and C = Mn2+ or Fe2+. The end-member formulae of approved rhodonite-group minerals are as follows: rhodonite CaMn3Mn[Si5O15]; ferrorhodonite CaMn3Fe[Si5O15]; and vittinkiite MnMn3Mn[Si5O15].

scholarly journals Kishonite, VH2, and Oreillyite, Cr2N, Two New Minerals from the Corundum Xenocrysts of Mt Carmel, Northern Israel

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1118
Author(s):  
Luca Bindi ◽  
Fernando Cámara ◽  
Sarah E. M. Gain ◽  
William L. Griffin ◽  
Jin-Xiang Huang ◽  
...  
Keyword(s):  
Single Crystal ◽  
Volatile Species ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
International Mineralogical Association ◽  
Mineralogical Association ◽  
Transmission Electron ◽  
Deep Earth

Here, we describe two new minerals, kishonite (VH2) and oreillyite (Cr2N), found in xenoliths occurring in pyroclastic ejecta of small Cretaceous basaltic volcanoes exposed on Mount Carmel, Northern Israel. Kishonite was studied by single-crystal X-ray diffraction and was found to be cubic, space group Fm3¯m, with a = 4.2680(10) Å, V = 77.75(3) Å3, and Z = 4. Oreillyite was studied by both single-crystal X-ray diffraction and transmission electron microscopy and was found to be trigonal, space group P3¯1m, with a = 4.7853(5) Å, c = 4.4630(6) Å, V = 88.51 Å3, and Z = 3. The presence of such a mineralization in these xenoliths supports the idea of the presence of reduced fluids in the sublithospheric mantle influencing the transport of volatile species (e.g., C, H) from the deep Earth to the surface. The minerals and their names have been approved by the Commission of New Minerals, Nomenclature and Classification of the International Mineralogical Association (No. 2020-023 and 2020-030a).

Classification of the minerals of the graftonite group

2018 ◽  
Vol 82 (6) ◽  
pp. 1301-1306 ◽  
Author(s):  
Frank C. Hawthorne ◽  
Adam Pieczka
Keyword(s):  
Crystal Structures ◽  
Distinct Species ◽  
International Mineralogical Association ◽  
Coordination Numbers ◽  
Mineralogical Association ◽  
Strong Order

ABSTRACTA classification and nomenclature scheme has been approved by the International Mineralogical Association Commission on New Minerals, Nomenclature and Classification for the minerals of the graftonite group. The crystal structures of these minerals have three distinct sites that are occupied by Fe2+, Mn2+and Ca2+. These sites have coordination numbers [8], [5] and [6], and these differences lead to very strong order of Fe2+, Mn2+and Ca2+over these sites. As a result of this strong order, the following compositions have been identified as distinct species: graftonite: FeFe2(PO4)2; graftonite-(Ca): CaFe2(PO4)2; graftonite-(Mn): MnFe2(PO4)2; beusite: MnMn2(PO4)2; and beusite-(Ca): CaMn2(PO4)2.

Structural, chemical and spectroscopic re-examination of type uklonskovite leads to its redefinition

2017 ◽  
Vol 81 (6) ◽  
pp. 1397-1404 ◽  
Author(s):  
S. Menchetti ◽  
L. Bindi ◽  
D. Belakovskiy ◽  
F. Zaccarini
Keyword(s):  
Crystal Structure ◽  
Scientific Literature ◽  
Careful Analysis ◽  
Chemical Formula ◽  
International Mineralogical Association ◽  
Mineralogical Association ◽  
Structural Details ◽  
First Time ◽  
Shed Light

AbstractThe crystal structure and the chemical composition of uklonskovite from the holotype material was reinvestigated to shed light on its correct chemical formula. On the basis of information gained from this characterization, we revised the formula from NaMg(SO4)OH·2H2O to NaMg(SO4)F·2H2O (F instead of OH). A careful analysis of the structural details together with a critical review of all the chemical data listed in the scientific literature for uklonskovite support our redefinition. We also present Raman data for the mineral for the first time. Our proposal was approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (voting proposal 16-J).

Mesaite, (V2O7)3·12H2O, a new vanadate mineral from the Packrat mine, near Gateway, Mesa County, Colorado, USA

2017 ◽  
Vol 81 (2) ◽  
pp. 319-327 ◽  
Author(s):  
Anthony R. Kampf ◽  
Barbara P. Nash ◽  
Joe Marty ◽  
John M. Hughes
Keyword(s):  
Powder Diffraction ◽  
New Mineral ◽  
Formula Unit ◽  
International Mineralogical Association ◽  
Mineralogical Association ◽  
Interlayer Region ◽  
Perfect Cleavage ◽  
Mohs Hardness ◽  
Measured Density

AbstractMesaite (IMA2015-069), ideally (V2O7)3·12H2O, is a new mineral from the Packrat mine, Gateway district, Mesa County, Colorado, USA. Crystals of mesaite occur as orangish red blades up to 0.1 mm long and ∼10 μm thick. The streak is light pinkish orange and the lustre is vitreous, transparent. Mesaite has a brittle tenacity, {010} perfect cleavage; fracture is irregular, and no parting was observed. The mineral has a Mohs hardness ≈ 2. The measured density of mesaite is 2.74(1) g cm–3. Mesaite is biaxial (–), α = 1.760(calc), β = 1.780(5), γ = 1.795(5) in white light; the measured 2V value = 81(2)°. Dispersion is strong, r < v, and pleochroism is present in shades of brownish orange. Mesaite is monoclinic, P2/n, with a = 9.146(2), b = 10.424(3), c = 15.532(4) Å, β = 102.653(7)° and V = 1444.7(6) Å3. The strongest four diffraction lines in the powder diffraction pattern are [(dobs in Å, (Iobs), (hkl)]: 10.47 (100) (010), 2.881 (25) (132, 3̄12, 033, 310), 3.568 (24) (1̄14, 1̄23, 2̄13), 3.067 (17) (1̄24, 1̄32, 2̄23). The composition of mesaite was determined by electron microprobe, and yielded an empirical formula of Mn5.32Ca0.56Zn0.31V5.96As0.04O33H23.61 on the basis of 33 O atoms per formula unit (apfu).The atomic arrangement of mesaite was solved and refined to R1 = 0.0600. The structure is formed of zigzag octahedral chains of edge-sharing Mn2+O6 octahedra. Oxygen atoms of the octahedra are shared with V2O7 groups, which link with adjacent octahedral chains to form {010} heteropolyhedral layers. The interlayer region contains Ca atoms and H2O groups. Each Ca bonds to two O6 atoms in the heteropolyhedral layer and to two fully occupied and six partially occupied O (H2O) sites in the interlayer, resulting in an effective Ca coordination of approximately seven. Similar zigzag chains of edge-sharing MnO6 octahedra decorated with V2O7 groups are also found in the mineral fianelite. Mesaite has beenapproved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA2015-069). The name mesaite is conferred for Mesa County, Colorado, USA.

scholarly journals Review of tetrahedrites from Bulgarian deposits in the light of changes in nomenclature and classification of these minerals taken in 2019

2020 ◽  
Vol 81 (1) ◽  
pp. 3-15
Author(s):  
Vladislav Kostov-Kytin
Keyword(s):  
Spatial Distribution ◽  
Chemical Composition ◽  
Electron Probe ◽  
Mineral Species ◽  
Published Data ◽  
Crystal Chemical ◽  
International Mineralogical Association ◽  
Mineralogical Association ◽  
Chemical Trends

The crystal-chemical peculiarities of the minerals in the tetrahedrite group are considered as a prerequisite for their role as indicators of the formation environment. Particular attention is paid to the silver-containing representatives because they comprise more than 60% of the Bulgarian tetrahedrites and because the recently adopted by the International Mineralogical Association changes in the nomenclature and classification within this group affect most sensitively them and their relation to a given series, mineral species or variety. The achievements of the Bulgarian mineralogical science in the study of tetrahedrites are briefly presented, and various aspects are considered, illustrating the efforts of the researchers to cover the diversity of these minerals as well as the opportunity to derive from this various crystal-chemical, geochemical and other mineralogical information. In the light of the adopted changes, already published data from 450 electron-probe microanalyses of samples from 45 localities distributed in three metallogenic zones in the country have been processed. The established crystal-chemical trends in the spatial distribution of tetrahedrites in Bulgaria generally confirm and extend the observations of previous researchers. It has been shown that, by their chemical composition, these minerals can be carriers of typomorphic characteristics, both for individual deposits and for metallogenic zones. The information and data provided may serve to: (i) correctly determine the mineral species of the newly investigated tetrahedrites and their affiliation to a given series; (ii) what compositions may be sought or expected according to the location of the investigated localities; (iii) comparing the new results to previous ones to confirm, correct or reject established models and trends.

A comment on “An evolutionary system of mineralogy: Proposal for a classification of planetary materials based on natural kind clustering”

2021 ◽  
Vol 106 (1) ◽  
pp. 150-153
Author(s):  
Frédéric Hatert ◽  
Stuart J. Mills ◽  
Frank C. Hawthorne ◽  
Mike S. Rumsey
Keyword(s):  
Mineral Species ◽  
New Mineral ◽  
Evolutionary System ◽  
Species Classification ◽  
Classification Schemes ◽  
International Mineralogical Association ◽  
Mineralogical Association ◽  
New Mineral Species ◽  
Planetary Materials

Abstract The classification and nomenclature of mineral species is regulated by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMACNMNC). This mineral species classification is necessary for Earth Sciences, as minerals constitute most planetary and interstellar materials. Hazen (2019) has proposed a classification of minerals and other Earth and planetary materials according to “natural clustering.” Although this classification is complementary to the IMA-CNMNC mineral classification and is described as such, there are some unjustified criticisms and factual errors in the comparison of the two schemes. It is the intent of the present comment to (1) clarify the use of classification schemes for Earth and planetary materials, and (2) counter erroneous criticisms or statements about the current IMA-CNMNC system of approving proposals for new mineral species and classifications.

Chemographic exploration of the hyalotekite structure-type

2018 ◽  
Vol 82 (4) ◽  
pp. 929-937
Author(s):  
Frank C. Hawthorne ◽  
Elena Sokolova ◽  
Atali A. Agakhanov ◽  
Leonid A. Pautov ◽  
Vladimir Yu. Karpenko ◽  
...  
Keyword(s):  
Structure Refinement ◽  
Chemical Properties ◽  
Structure Type ◽  
International Mineralogical Association ◽  
Mineralogical Association ◽  
Coordination Sites ◽  
Bond Topology ◽  
Triclinic Structure ◽  
High Coordination

ABSTRACTThe hyalotekite group has been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (memorandum 57–SM/16). The general formula of the minerals of the hyalotekite group may be written as: A2B2M2[Si8T4O28]W where A = Ba2+, Pb2+ or K+; B = Ba2+, Pb2+ or K+; M = Ca2+, Y3+ or REE3+; T = Si4+, B3+ or Be2+; and W = F– or □ (where REE = rare-earth elements and □ = vacancy).Four minerals are currently known in this group: hyalotekite, Ba4Ca2[Si8B2(SiB)O28]F, triclinic, I$\bar 1$; khvorovite, Pb2+4Ca2[Si8B2(SiB)O28]F, triclinic I$\bar 1$; kapitsaite-(Y), Ba4(YCa)[Si8B2B2O28]F, triclinic, I$\bar 1$; and itsiite Ba4Ca2[Si8B4O28]□, tetragonal, I$\bar 4$2m.We explore the possible end-member compositions within this group by conflating the properties of an end-member with the stoichiometry imposed by the bond topology of the hyalotekite structure-type and the crystal-chemical properties of its known constituents. There are two high-coordination sites in the hyalotekite structure, A and B, and occupancy of each of these sites can be determined only by crystal-structure refinement. If these two sites are considered together, there are 19 end-member compositions of the triclinic structure and six end-member compositions of the tetragonal structure involving A and B = Ba2+, Pb2+, K+; M = Ca2+, Y3+, REE3+; and T = Si4+, B3+, Be2+. There is the possibility for many other hyalotekite-group minerals, and two potential new minerals have been identified from data in the literature.

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).

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