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.

scholarly journals The discovery of new mineral species and type minerals from Brazil

2015 ◽  
Vol 45 (1) ◽  
pp. 143-158 ◽  
Author(s):  
Daniel Atencio
Keyword(s):  
Iron Ore ◽  
18Th Century ◽  
Mineral Species ◽  
New Mineral ◽  
Synthetic Analogue ◽  
Copper Ore ◽  
International Mineralogical Association ◽  
Mineralogical Association ◽  
New Mineral Species ◽  
Wide Range

Minerals were seen merely as sources of chemicals: iron ore, copper ore, etc. However, minerals are not just chemicals associations, since they display crystal structures. These two features together provide properties that can be technologically useful. Even though a mineral occurs in very small amount, which does not allow its extraction, it can serve as a model for obtaining the synthetic analogue on an industrial scale. It is necessary that a new-mineral proposal be submitted for approval by the Commission on New Minerals, Nomenclature and Classification (CNMNC) of the International Mineralogical Association (IMA) before publication. Only 65 valid mineral species were first described from Brazil, that is, the type minerals from Brazil. Nineteen of these were published between 1789 and 1959 (0.11 per year). From 1959, when the CNMMN (today CNMNC) - IMA was established, to 2000, 18 approved Brazilian mineral species remain valid (0.43 per year). However, the number of type minerals from Brazil approved in the last 15 years (2000 to 2014) was substantially increased: 28 (1.87 per year). This number is very small considering the wide range of Brazilian geological environments. The two first type species from Brazil, discovered in the 18th century, chrysoberyl and euclase, are important gemological minerals. Two other gem minerals, tourmaline-supergroup members, were published only in the 21st century: uvite and fluor-elbaite. Some type minerals from Brazil are very important technologically speaking. Some examples are menezesite, coutinhoite, lindbergite, pauloabibite, and waimirite-(Y).

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 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. 

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.

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 Spiridonovite, (Cu1-xAgx)2Te (x ≈ 0.4), a New Telluride from the Good Hope Mine, Vulcan, Colorado (U.S.A.)

Minerals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 194
Author(s):  
Marta Morana ◽  
Luca Bindi
Keyword(s):  
Crystal Structure ◽  
Vickers Hardness ◽  
Maximum Size ◽  
Unit Cell ◽  
New Mineral ◽  
Unit Cell Parameters ◽  
International Mineralogical Association ◽  
Cell Parameters ◽  
Mineralogical Association

Here we describe a new mineral in the Cu-Ag-Te system, spiridonovite. The specimen was discovered in a fragment from the cameronite [ideally, Cu5-x(Cu,Ag)3+xTe10] holotype material from the Good Hope mine, Vulcan, Colorado (U.S.A.). It occurs as black grains of subhedral to anhedral morphology, with a maximum size up to 65 μm, and shows black streaks. No cleavage is observed and the Vickers hardness (VHN100) is 158 kg·mm-2. Reflectance percentages in air for Rmin and Rmax are 38.1, 38.9 (471.1 nm), 36.5, 37.3 (548.3 nm), 35.8, 36.5 (586.6 nm), 34.7, 35.4 (652.3 nm). Spiridonovite has formula (Cu1.24Ag0.75)Σ1.99Te1.01, ideally (Cu1-xAgx)2Te (x ≈ 0.4). The mineral is trigonal and belongs to the space group P-3c1, with the following unit-cell parameters: a = 4.630(2) Å, c = 22.551(9) Å, V = 418.7(4) Å 3, and Z = 6. The crystal structure has been solved and refined to R1 = 0.0256. It can be described as a rhombohedrally-compressed antifluorite structure, with a rough ccp arrangement of Te atoms. It consists of two Te sites and three M (metal) sites, occupied by Cu and Ag, and is characterized by the presence of edge-sharing tetrahedra, where the four-fold coordinated M atoms lie. The mineral and its name have been approved by the Commission of New Minerals, Nomenclature and Classification of the International Mineralogical Association (No. 2018-136).

Arsenic-bearing new mineral species from Valletta mine, Maira Valley, Piedmont, Italy: I. Grandaite, Sr2Al(AsO4)2(OH), description and crystal structure

2014 ◽  
Vol 78 (3) ◽  
pp. 757-774 ◽  
Author(s):  
F. Cámara ◽  
M. E. Ciriotti ◽  
E. Bittarello ◽  
F. Nestola ◽  
F. Massimi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Divalent Cations ◽  
Crystal Structure Analysis ◽  
Mineral Species ◽  
New Mineral ◽  
Monoclinic Space Group ◽  
Calculated Density ◽  
Oh Groups ◽  
International Mineralogical Association ◽  
New Mineral Species

AbstractThe new mineral species grandaite, ideally Sr2Al(AsO4)2(OH), has been discovered on the dump of Valletta mine, Maira Valley, Cuneo province, Piedmont, Italy. Its origin is related to the reaction between the ore minerals and hydrothermal solutions. It occurs in thin masses of bright orange to salmon to brown coloured crystals, or infrequently as fan-like aggregates of small (<1 mm) crystals, with reddish-brown streak and waxy to vitreous lustre. Grandaite is associated with aegirine, baryte, braunite, hematite, tilasite, quartz, unidentified Mn oxides and Mn silicates under study.Grandaite is biaxial (+) with refractive indices α = 1.726(1), β = 1.731(1), γ = 1.752(1). Its calculated density is 4.378 g/cm3. Grandaite is monoclinic, space groupP21/m, witha= 7.5764(5),b= 5.9507(4),c= 8.8050(6) Å, β = 112.551(2)°,V= 366.62(4) Å3andZ= 2. The eight strongest diffraction lines of the observed X-ray powder diffraction pattern are [din Å, (I), (hkl)]: 3.194 (100)(11), 2.981 (50.9)(020), 2.922 (40.2)(03), 2.743 (31.4)(120), 2.705 (65.2)(112), 2.087 (51.8) (23), 1.685 (24.5)(321), 1.663 (27.7)(132). Chemical analyses by electron microprobe gave (wt.%) SrO 29.81, CaO 7.28, BaO 1.56, Al2O37.07, Fe2O32.34, Mn2O31.88, MgO 1.04, PbO 0.43, As2O544.95, V2O50.50, P2O50.09, sum 96.95; H2O 1.83 wt.% was calculated by stoichiometry from the results of the crystal-structure analysis. Raman and infrared spectroscopies confirmed the presence of (AsO4)3−and OH groups. The empirical formula calculated on the basis of 9 O a.p.f.u., in agreement with the structural results, is (Sr1.41Ca0.64Ba0.05Pb0.01)∑=2.11(Al0.68Fe0.143+Mn0.123+Mg0.13)∑=1.07[(As0.96V0.01)∑=0.97O4]2(OH), the simplified formula is (Sr,Ca)2(Al,Fe3+)(AsO4)2(OH) and the ideal formula is Sr2Al(AsO4)2(OH).The crystal structure was solved by direct methods and found to be topologically identical to that of arsenbrackebuschite. The structure model was refined on the basis of 1442 observed reflections toR1= 2.78%. In the structure of grandaite, chains of edge-sharingM3+octahedra run along [010] and share vertices with T5+tetrahedra, building up [M3+(T5+O4)2(OH, H2O)] units, which are connected through interstitial divalent cations. Grandaite is named after the informal appellation of the province where the type locality is located. The new mineral was approved by the International Mineralogical Association Commission on New Minerals, Nomenclature and Classification (IMA2013-059). The discovery of grandaite and of other members of the group (description still in progress) opens up the possibility of exploring the crystal chemistry of the brackebuschite supergroup.

scholarly journals Freitalite, C<sub>14</sub>H<sub>10</sub>, a new aromatic hydrocarbon mineral from Freital, Saxony, Germany

2021 ◽  
Vol 33 (1) ◽  
pp. 1-8
Author(s):  
Thomas Witzke ◽  
Martin Schreyer ◽  
Benjamin Brandes ◽  
René Csuk ◽  
Herbert Pöllmann
Keyword(s):  
Aromatic Hydrocarbon ◽  
High Performance ◽  
New Mineral ◽  
Low Oxygen ◽  
Calculated Density ◽  
International Mineralogical Association ◽  
New Mineral Species ◽  
Nmr Spectrometry ◽  
Infrared And Raman Spectroscopy

Abstract. The new mineral species freitalite, C14H10, corresponding to the aromatic hydrocarbon anthracene, has been discovered on the mine dump of the Königin Carola shaft (also named Paul Berndt Mine), Freital, near Dresden, Saxony, Germany. The mineral forms thin blades or flakes of irregular shape up to a few millimetres in size and shows an intense violet or whitish-violet to white colour. Freitalite is a product of pyrolysis of coal at low oxygen fugacity and was formed by sublimation from a gas phase. The mineral is associated with sulfur and hoelite. Elemental analysis gave (in wt. %, average of three analyses) C 94.07, H 5.571 and total 99.641. The empirical formula is C14.00H9.88 (calculated for C = 14). The identity with anthracene was confirmed by infrared and Raman spectroscopy, high-performance liquid chromatography, gas chromatography with mass spectrometry, 1H and 13C NMR spectrometry, and X-ray powder diffraction. Freitalite is monoclinic, P21∕a, with lattice parameters a=8.5572(9), b=6.0220(5), c=11.173(1) Å, β=124.174(1)∘ and V=476.34(3) Å3 refined from powder data. The calculated density of 1.242 g cm−3 (for Z=2) is very close to the measured density of 1.240 g cm−3. Freitalite was accepted as a new mineral by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA 2019-116).

scholarly journals As-bearing new mineral species from Valletta mine, Maira Valley, Piedmont, Italy: III. Canosioite, Ba2Fe3+(AsO4)2(OH), description and crystal structure

2017 ◽  
Vol 81 (2) ◽  
pp. 305-317 ◽  
Author(s):  
F. Cámara ◽  
E. Bittarello ◽  
M. E. Ciriotti ◽  
F. Nestola ◽  
F. Radica ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Direct Methods ◽  
Mineral Species ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Calculated Density ◽  
International Mineralogical Association ◽  
New Mineral Species ◽  
Ore Minerals ◽  
Mn Oxides

AbstractThe new mineral species canosioite, ideally Ba2Fe3+(AsO4)2(OH), has been discovered in the dump of Valletta mine, Maira Valley, Cuneo Province, Piedmont, Italy. Its origin is probably related to the reaction between ore minerals and hydrothermal fluids. It occurs in reddish-brown granules, subhedral millimetre-size crystals, with a pale yellow streak and vitreous lustre. Canosioite is associated with aegirine, baryte, calcite, hematite, bronze Mn-bearing muscovite, unidentified Mn oxides and unidentified arsenates. Canosioite is biaxial (+) with a 2Vmeas= 84(2)°. It is weakly pleochroic withX= brownish yellow,Y= brown,Z= reddish brown,Z>Y>X. Canosioite is monoclinic,P21/m, witha= 7.8642(4),b= 6.1083(3),c= 9.1670(5) Å, β = 112.874(6)°,V= 405.73(4) Å3andZ= 2. Calculated density is 4.943 g cm–3. The seven strongest diffraction lines of the observed powder X-ray diffraction pattern are [din Å, (I) (hkl)]: 3.713 (18)(111), 3.304 (100)(211̄), 3.058 (31)(020), 3.047 (59)(103̄), 2.801 (73)(112), 2.337 (24)(220), 2.158 (24)(123̄). Electron microprobe analyses gave (wt.%): Na2O 0.06, MgO 0.43, CaO 0.02, NiO 0.02, CuO 0.03, SrO 0.42, BaO 49.36, PbO 1.69, Al2O31.25, Mn2O33.89, Fe2O36.95, Sb2O30.01, SiO20.03, P2O50.02, V2O510.88, As2O524.64, SO3 0.01, F 0.02, H2O1.61 was calculated on the basis of 1 (OH,F,H2O) group per formula unit. Infrared spectroscopy confirmed the presence of OH. The empirical formula calculated on the basis of 9 O apfu, is (Ba1.92Pb0.05Sr0.02Na0.01)∑2.00(Fe0.523+Mn0.293+Al0.15Mg0.06)∑1.02[(As0.64V0.36)∑1.00O4]2[(OH0.92F0.01)(H2O)0.07]and the ideal formula is Ba2Fe3+(AsO4)2(OH). The crystal structure was solved by direct methods and found to be isostructural to that of arsenbrackebuschite. The structure model was refined (R1= 2.6%) on the basis of 1245 observed reflections. Canosioite is named after the small municipality of Canosio, where the type locality, the Valletta mine, is situated. The new mineral and name were approved by the International Mineralogical Association Commission on New Minerals and Mineral Names (IMA2015-030).

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