scholarly journals Joteite, Ca2CuAl[AsO4][AsO3(OH)]2(OH)2·5H2O, a new arsenate with a sheet structure and unconnected acid arsenate groups

2013 ◽  
Vol 77 (6) ◽  
pp. 2811-2823 ◽  
Author(s):  
A. R. Kampf ◽  
S. J. Mills ◽  
R. M. Housley ◽  
G. R. Rossman ◽  
B. P. Nash ◽  
...  
Keyword(s):  
Empirical Formula ◽  
New Mineral ◽  
Optical Orientation ◽  
Secondary Mineral ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
Perfect Cleavage ◽  
Mohs Hardness ◽  
Greenish Blue

AbstractJoteite (IMA2012-091), Ca2CuAl[AsO4][AsO3(OH)]2(OH)2·5H2O, is a new mineral from the Jote mine, Tierra Amarilla, Copiapó Province, Atacama, Chile. The mineral is a late-stage, low-temperature, secondary mineral occurring with conichalcite, mansfieldite, pharmacoalumite, pharmacosiderite and scorodite in narrow seams and vughs in the oxidized upper portion of a hydrothermal sulfide vein hosted by volcanoclastic rocks. Crystals occur as sky-blue to greenish-blue thin blades, flattened and twinned on {001}, up to ~300 μm in length, and exhibiting the forms {001}, {010}, {10}, {20} and {111}. The blades are commonly intergrown in wheat-sheaf-like bundles, less commonly in sprays, and sometimes aggregated as dense crusts and cavity linings. The mineral is transparent and has a very pale blue streak and vitreous lustre. The Mohs hardness is estimated at 2 to 3, the tenacity is brittle, and the fracture is curved. It has one perfect cleavage on {001}. The calculated density based on the empirical formula is 3.056 g/cm3. It is optically biaxial (–) with α = 1.634(1), β = 1.644(1), γ = 1.651(1) (white light), 2Vmeas = 78(2)° and 2Vcalc = 79.4°. The mineral exhibits weak dispersion, r < v. The optical orientation is X ≈ c*; Y ≈ b*. The pleochroism is Z (greenish blue) > Y (pale greenish blue) > X (colourless). The normalized electron-microprobe analyses (average of 5) provided: CaO 15.70, CuO 11.22, Al2O38.32, As2O546.62, H2O 18.14 (structure), total 100 wt.%. The empirical formula (based on 19 O a.p.f.u.) is: Ca1.98Cu1.00Al1.15As2.87H14.24O19. The mineral is slowly soluble in cold, concentrated HCl. Joteite is triclinic, P1, with the cell parameters: a = 6.0530(2), b = 10.2329(3), c = 12.9112(4) Å, α = 87.572(2), β = 78.480(2), γ = 78.697(2)°, V = 768.40(4) Å3 and Z = 2. The eight strongest lines in the X-ray powder diffraction pattern are [dobs Å (I)(hkl)]: 12.76(100)(001), 5.009(23)(020), 4.206(26)(120,003,121), 3.92(24)(022,02,02), 3.40(25)(1̄13), 3.233(19)(031,023,123,02̄3), 2.97(132,201) and 2.91(15)(22,13). In the structure of joteite (R1 = 7.72% for 6003 Fo > 4σF), AsO4 and AsO3 (OH) tetrahedra, AlO6 octahedra and Cu2+O5 square pyramids share corners to form sheets parallel to {001}. In addition, 7- and 8-coordinate Ca polyhedra link to the periphery of the sheets yielding thick slabs. Between the slabs are unconnected AsO3(OH) tetrahedra, which link the slabs only via hydrogen bonding. The Raman spectrum shows features consistent with OH and/or H2O in multiple structural environments. The region between the slabs may host excess Al in place of some As.

Vysokýite, U4+[AsO2(OH)2]4·4H2O, a new mineral from Jáchymov, Czech Republic

2013 ◽  
Vol 77 (8) ◽  
pp. 3055-3066 ◽  
Author(s):  
J. Plášil ◽  
J. Hloušek ◽  
R. Škoda ◽  
M. Novák ◽  
J. Sejkora ◽  
...  
Keyword(s):  
Czech Republic ◽  
Single Crystal ◽  
Empirical Formula ◽  
New Mineral ◽  
Wavelength Dispersive Spectroscopy ◽  
Oh Groups ◽  
X Ray ◽  
Cell Parameters ◽  
Perfect Cleavage ◽  
Mohs Hardness

AbstractVysokýite, U4+[(AsO2(OH)2]4(H2O)4 (IMA 2012–067), was found growing on an altered surface of massive native As in the Geschieber vein, Jáchymov ore district, Western Bohemia, Czech Republic. The new mineral was found in association with běhounekite, štěpite, kaatialaite, arsenolite, claudetite and gypsum. It forms extremely fibrous light-green crystals up to 8 mm long. Crystals have an alabaster lustre and a greenish-white to greyish streak. Vysokýite is brittle with uneven fracture and perfect cleavage along (100) and (001); the Mohs hardness is ∼2. A density of 3.393 g/cm3 was calculated using the empirical formula and unit-cell parameters obtained from a single-crystal diffraction experiment. Vysokýite is non-fluorescent under short or long wavelength UV radiation. It is colourless under the microscope, measured refractive indices are α' = 1.617(3), γ' = 1.654(3); the estimated optical orientation is α' ∼X, γ' ∼Z. The average of five spot wavelength dispersive spectroscopy (WDS) analyses is 29.44 UO2, 1.03 SiO2, 48.95 As2O5, 0.12 SO3, 15.88 H2O (calc.), total 95.42 wt.%. The empirical formula of vysokýite (based on 20 O a.p.f.u.) is U1.00[AsO2(OH)2]3.90(SiO4)0.16 (SO4)0.01·4H2O. The As–O–H and O–H vibrations dominate in the Raman spectrum. Vysokýite is triclinic, space group P, with a = 10.749(2), b = 5.044(3), c = 19.1778(7) Å, α = 89.872(15)°, β = 121.534(15)°, γ = 76.508(15)°, and V = 852.1(6) Å3, Z = 2 and Dcalc = 3.34 g·cm–3. The strongest diffraction peaks in the X-ray powder diffraction pattern are [dobs in Å (Irel.)(hkl)]: 8.872(100)(100), 8.067(50)(002), 6.399(7)(10), 4.773(6)(10), 3.411(10)(30), 3.197(18)(31). The crystal structure of vysokýite was solved from single-crystal X-ray diffraction data by the charge-flipping method and refined to R1 = 0.0595 based on 2718 unique observed reflection, and to wR2 = 0.1160 for all 4173 unique reflections. The structure of vysokýite consists of UO8 square antiprisms sharing all of their vertices with 8 As-tetrahedra to form infinite chains parallel to [010]. These chains are linked by hydrogen bonds involving terminal (OH) groups of the double-protonated As-tetrahedra and molecules of H2O located between the chains. The new mineral is named in honour of Arnošt Vysoký (1823–1872), the former chief of the Jáchymov mines and smelters, chemist and metallurgist.

Kurilite – Ag8Te3Se – a new mineral from the Prasolovskoe deposit, Kuril islands, Russian Federation

2010 ◽  
Vol 74 (3) ◽  
pp. 463-468 ◽  
Author(s):  
V. A. Kovalenker ◽  
O. Yu. Plotinskaya ◽  
C. J. Stanley ◽  
A. C. Roberts ◽  
A. M. McDonald ◽  
...  
Keyword(s):  
Russian Federation ◽  
Empirical Formula ◽  
Polarized Light ◽  
New Mineral ◽  
Unit Cell Parameters ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
Kunashir Island ◽  
Mohs Hardness

AbstractKurilite, with the simplified formula, Ag8Te3Se, is a new mineral from the Prasolovskoe epithermal Au-Ag deposit, Kunashir Island, Kuril arc, Russian Federation. It occurs as aggregates up to 2 mm in size, composed of brittle xenomorphic grains, up to several μm in size, in quartz, associated with tetrahedrite, hessite, sylvanite and petzite. Kurilite is opaque, grey, with a metallic lustre and a black streak. Under plane-polarized light, kurilite is white with no observed bireflectance, cleavage, or parting observed. Under crossed polars it appears isotropic without internal reflections. Reflectance values in air and in oil, are tabulated. It has a mean VHN (25 g load) of 99.9 kg/mm2 which equates roughly to a Mohs hardness of 3. Electron microprobe analyses yield a mean composition of Ag 63.71, Au 0.29, Te 29.48, Se 5.04, S 0.07, total 98.71 wt.%. The empirical formula (based on 12 atoms) is (Ag7.97Au0.02)Σ7.99Te3.00(Se0.86Te0.12S0.03)Σ1.01. The calculated density is 7.799 g/cm3 (based on the empirical formula and unit-cell parameters refined from single-crystal data). Kurilite is rhombohedral, R3 or , a 15.80(1), c 19.57(6) Å, V 4231(12)Å3, c:a 1.2386, Z = 15. Its crystal structure remains unsolved. The seven strongest lines of the X-ray powder-diffraction pattern [d in Å (I)(hkl)] are: 3.727(20)(131), 2.996(50)(232), 2.510(30)(226,422), 2.201(100)(128,416,342), 2.152(20)(603), 2.079(30)(253), 2.046(20)(336,434). The mineral is named after the locality.

Fassinaite, Pb22+(S2O3)(CO3), the first mineral with coexisting thiosulphate and carbonate groups:d escription and crystal structure

2011 ◽  
Vol 75 (6) ◽  
pp. 2721-2732 ◽  
Author(s):  
L. Bindi ◽  
F. Nestola ◽  
U. Kolitsch ◽  
A. Guastoni ◽  
F. Zorzi
Keyword(s):  
Empirical Formula ◽  
Optical Data ◽  
New Mineral ◽  
Orthorhombic Space Group ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
Mohs Hardness ◽  
Ray Density ◽  
Oxygen Atoms

AbstractFassinaite, ideally Pb22+(S2O3)(CO3), is a new mineral from the Trentini mine, Mount Naro, Vicenza Province, Veneto, Italy (holotype locality). It is also reported from the Erasmus adit, Schwarzleo District, Leogang, Salzburg, Austria and the Friedrich-Christian mine, Schapbach, Black Forest, Baden-Wurttemberg, Germany (cotype localities). At the Italian type locality it occurs as acicular [010]. colourless crystals up to 200 μn long, closely associated with galena, quartz and anglesite. At the Austrian cotype locality it is associated with cerussite, rare sulphur and very rare phosgenite. At the German cotype locality anglesite is the only associated phase. Fassinaite crystals commonly have flat chisel-shaped terminations. They are transparent with vitreous to adamantine lustre and a white streak. Fassinaite is brittle with an irregular fracture and no discernible cleavage; the estimated Mohs hardness is 11/2—2. The calculated density for the type material is 6.084 g cm–3 (on the basis of the empirical formula), whereas the X-ray density is 5.947 g cm–3. In common with other natural lead thiosulphates (i.e. sidpietersite and steverustite) fassinaite has intense internal reflections, which do not allow satisfactory optical data to be collected; the crystals are length-slow and have very high birefringence. The mineral is not fluorescent.Fassinaite is orthorhombic, space group Pnma, with unit-cell parameters (for the holotype material) a = 16.320(2), b = 8.7616(6), c = 4.5809(7) Å, V = 655.0(1) Å3, a:b:c = 1.863:1:0.523, Z = 4. Single-crystal structural studies were carried out on crystals from all three localities: R1(F) values range between 0.0353 and 0.0596. The structure consists of rod-like arrangements of Pb-centred polyhedra that extend along the [010] direction. These ‘rods’ are linked, alternately, by (CO3)2– and (S2O3)2– groups. The (S2O3)2– groups point alternately left and right (in a projection on [001] with [010] set vertical) if the apex occupied by the S2– in the thiosulphate group is defined to be the atom giving the direction. The lead atoms are nine-coordinated by seven oxygen atoms and two sulphur (S2–) atoms. The eight strongest X-ray powder-diffraction lines [d in Å (I/I0) (hkl)] are: 4.410 (39) (101), 4.381 (59) (020), 4.080 (62) (400), 3.504 (75) (301), 3.108 (100) (121), 2.986 (82) (420), 2.952 (49) (221) and 2.736 (60) (321). Electron-microprobe analyses produce an empirical formula Pb2.01(1)(S1.82(2)O3)CO3 (on the basis of six oxygen atoms). The presence of both carbonate and thiosulphate groups was corroborated by Raman spectra, which are discussed in detail. Fassinaite is named after Bruno Fassina (b. 1943), an Italian mineral collector who discovered the mineral in 2009.

Leverettite from the Torrecillas mine, Iquique Provence, Chile: the Co-analogue of herbertsmithite

2013 ◽  
Vol 77 (7) ◽  
pp. 3047-3054 ◽  
Author(s):  
A. R. Kampf ◽  
M. J. Sciberras ◽  
P. A. Williams ◽  
M. Dini ◽  
A. A. Molina Donoso
Keyword(s):  
Empirical Formula ◽  
New Mineral ◽  
Calculated Density ◽  
Cell Parameters ◽  
Conchoidal Fracture ◽  
Bluish Green ◽  
Perfect Cleavage ◽  
Mohs Hardness ◽  
Deep Green ◽  
Light Green

AbstractThe new mineral leverettite (IMA 2013-011), ideally Cu3CoCl2(OH)6, was found at the Torrecillas mine, Salar Grande, Iquique Province, Chile, where it occurs as a supergene alteration phase in association with akaganéite, anhydrite, chalcophanite, goethite, halite, manganite, pyrite, quartz and todorokite. Crystals of leverettite are steep rhombohedra to 1 mm with {101} prominent and modified by {001}, sometimes forming V-shaped twins by reflection on {10}. The crystals can also form finger-like, parallel stacked growths along the c axis. The new mineral is medium to deep green in colour and has a light green streak. Crystals are transparent with a vitreous lustre. Mohs hardness is ∼3 and the crystals have a brittle tenacity, a perfect cleavage on {101} and a conchoidal fracture. The measured density is 3.64(2) g cm–3 and calculated density based on the empirical formula is 3.709 g cm–3. Optically, leverettite is uniaxial (–) with ω and ε > 1.8 and exhibits pleochroism with O (bluish green) > E (slightly yellowish green). The empirical formula, determined from electron-microprobe analyses is Cu3(Co0.43Cu0.40Mn0.17Ni0.07Mg0.01)Σ1.08Cl1.87O6.13H6. Leverettite is trigonal (hexagonal), space group Rm, unit-cell parameters a = 6.8436(6) and c = 14.064(1) Å, V = 570.42(8) Å3, Z = 3. The eight strongest X-ray powder diffraction lines are [dobs Å (I)(hkl)]: 5.469(90)(101), 4.701(18)(003), 2.905(22)(021), 2.766(100)(113), 2.269(66)(024), 1.822(26)(033), 1.711(33)(220), 1.383(23)(128). The structure, refined to R1 = 0.023 for 183 Fo > 4σF reflections, shows leverettite to be isostructural with herbertsmithite and gillardite.

scholarly journals Bluebellite and mojaveite, two new minerals from the central Mojave Desert, California, USA

2014 ◽  
Vol 78 (5) ◽  
pp. 1325-1340 ◽  
Author(s):  
S. J. Mills ◽  
A. R. Kampf ◽  
A. G. Christy ◽  
R. M. Housley ◽  
G. R. Rossman ◽  
...  
Keyword(s):  
Empirical Formula ◽  
Mojave Desert ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Calculated Density ◽  
Cell Parameters ◽  
Bluish Green ◽  
Perfect Cleavage ◽  
Mohs Hardness ◽  
Greenish Blue

AbstractBluebellite, Cu6[I5+O3(OH)3](OH)7Cl and mojaveite, Cu6[Te6+O4(OH)2](OH)7Cl, are new secondary copper minerals from the Mojave Desert. The type locality for bluebellite is the D shaft, Blue Bell claims, near Baker, San Bernardino County, California, while cotype localities for mojaveite are the E pit at Blue Bell claims and also the Bird Nest drift, Otto Mountain, also near Baker. The two minerals are very similar in their properties. Bluebellite is associated particularly with murdochite, but also with calcite, fluorite, hemimorphite and rarely dioptase in a highly siliceous hornfels. It forms bright bluishgreen plates or flakes up to ~20 mm 620 mm 65 mm in size that are usually curved. The streak is pale bluish green and the lustre is adamantine, but often appears dull because of surface roughness. It is non-fluorescent. Bluebellite is very soft (Mohs hardness ~1), sectile, has perfect cleavage on {001} and an irregular fracture. The calculated density based on the empirical formula is 4.746 g cm–3. Bluebellite is uniaxial (–), with mean refractive index estimated as 1.96 from the Gladstone-Dale relationship. It is pleochroic O (bluish green) >> E (nearly colourless). Electron microprobe analyses gave the empirical formula Cu5.82I0.99Al0.02Si0.12O3.11(OH)9.80Cl1.09based on 14 (O+Cl) a.p.f.u. The Raman spectrum shows strong iodate-related bands at 680, 611 and 254 cm–1. Bluebellite is trigonal, space group R3, with the unit-cell parameters: a = 8.3017(5), c = 13.259(1) Å , V = 791.4(1) Å 3 and Z = 3. The eight strongest lines in the powder X-ray diffraction (XRD) pattern are [dobs/Å (I) (hkl)]: 4.427(99)(003), 2.664(35)(211), 2.516(100)(212̄ ), 2.213(9)(006), 2.103(29)(033,214), 1.899(47)(312,215̄ ), 1.566(48)(140,217) and 1.479(29)(045,143̄ ,324).Mojaveite occurs at the Blue Bell claims in direct association with cerussite, chlorargyrite, chrysocolla, hemimorphite, kettnerite, perite, quartz and wulfenite, while at the Bird Nest drift, it is associated with andradite, chrysocolla, cerussite, burckhardtite, galena, goethite, khinite, mcalpineite, thorneite, timroseite, paratimroseite, quartz and wulfenite. It has also been found at the Aga mine, Otto Mountain, with cerussite, chrysocolla, khinite, perite and quartz. Mojaveite occurs as irregular aggregates of greenish-blue plates flattened on {001} and often curved, which rarely show a hexagonal outline, and also occurs as compact balls, from sky blue to medium greenish blue in colour. Aggregates and balls are up to 0.5 mm in size. The streak of mojaveite is pale greenish blue, while the lustre may be adamantine, pearly or dull, and it is non-fluorescent. The Mohs hardness is ~1. It is sectile, with perfect cleavage on {001} and an irregular fracture. The calculated density is 4.886 g cm–3, based on the empirical formulae and unit-cell dimensions. Mojaveite is uniaxial (–), with mean refractive index estimated as 1.95 from the Gladstone-Dale relationship. It is pleochroic O (greenish blue) >> E (light greenish blue). The empirical formula for mojaveite, based on 14 (O+Cl) a.p.f.u., is Cu5.92Te1.00Pb0.08Bi0.01O4(OH)8.94Cl1.06. The most intense Raman bands occur at 694, 654 (poorly resolved), 624, 611 and 254 cm–1. Mojaveite is trigonal, space group R3, with the unit-cell parameters: a = 8.316(2), c = 13.202(6) Å and V = 790.7(1) Å 3. The eight strongest lines in the powder XRD pattern are [dobs/Å (I) (hkl)]: 4.403(91)(003), 2.672(28)(211), 2.512(100)(212̄ ), 2.110(27)(033,214), 1.889(34)(312,215̄ ,223̄ ), 1.570(39)(404,140,217), 1.481(34)(045,143̄ ,324) and 1.338(14)(422). Diffraction data could not be refined, but stoichiometries and unit-cell parameters imply that bluebellite and mojaveite are very similar in crystal structure. Structure models that satisfy bondvalence requirements are presented that are based on stackings of brucite-like Cu6MX14layers, where M = (I or Te) and X = (O, OH and Cl). Bluebellite and mojaveite provide a rare instance of isotypy between an iodate containing I5+with a stereoactive lone electron pair and a tellurate containing Te6+with no lone pair.

Calciodelrioite, Ca(VO3)2(H2O)4, the Ca analogue of delrioite, Sr(VO3)2(H2O)4

2012 ◽  
Vol 76 (7) ◽  
pp. 2803-2817 ◽  
Author(s):  
A. R. Kampf ◽  
J. Marty ◽  
B. P. Nash ◽  
J. Plášil ◽  
A. V. Kasatkin ◽  
...  
Keyword(s):  
New Mineral ◽  
Unit Cell Parameters ◽  
The West ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
The Usa ◽  
Perfect Cleavage ◽  
Mohs Hardness ◽  
A Chain

AbstractCalciodelrioite, ideally Ca(VO3)2(H2O)4, is a new mineral (IMA 2012-031) from the uraniumvanadium deposits of the eastern Colorado Plateau in the USA. The type locality is the West Sunday mine, Slick Rock district, San Miguel County, Colorado. The new mineral occurs on fracture surfaces in corvusite- and montroseite-impregnated sandstone and forms as a result of the oxidative alteration of these phases. At the West Sunday mine, calciodelrioite is associated with celestine, gypsum, huemulite, metarossite, pascoite and rossite. The mineral occurs as transparent colourless needles, bundles of tan to brown needles and star bursts of nearly black broad blades composed of tightly intergrown needles. Crystals are elongate and striated parallel to [100], exhibiting the prismatic forms {001} and {011} and having terminations possibly composed of the forms {100} and {611̄}. The mineral is transparent and has a white streak, subadamantine lustre, Mohs hardness of about 2½, brittle tenacity, irregular to splintery fracture, one perfect cleavage on {001} and possibly one or more additional cleavages parallel to [100]. Calciodelrioite is soluble in water. The calculated density is 2.451 g cm– 3. It is optically biaxial (+) with α = 1.733(3), β = 1.775(3), γ = 1.825(3) (white light), 2Vmeas = 87.3(9)° and 2Vcalc = 87°. The optical orientation is X = b; Z ≈ a. No pleochroism was observed. Electronmicroprobe analyses of two calciodelrioite samples and type delrioite provided the empirical formulae (Ca0.88Sr0.07Na0.04K0.01)Σ1.00(V1.00O3)2(H2.01O)4, (Ca0.76Sr0.21Na0.01)Σ0.98(V1.00O3)2(H2.01O)4 and (Sr0.67Ca0.32)Σ0.99(V1.00O3)2(H2.00O)4, respectively. Calciodelrioite is monoclinic, I2/a, with unit-cell parameters a = 14.6389(10), b = 6.9591(4), c = 17.052(2) Å, β = 102.568(9)°, V = 1695.5(3) Å3 and Z = 8. The seven strongest lines in the X-ray powder diffraction pattern [listed as dobs Å (I)(hkl)] are as follows: 6.450(100)(011); 4.350(16)(013); 3.489(18)(020); 3.215(17)(022); 3.027(50)(multiple); 2.560(28)(4̄15,413); 1.786(18)(028). In the structure of calciodelrioite (refined to R1 = 3.14% for 1216 Fo > 4σF), V5+O5 polyhedra link by sharing edges to form a zigzag divanadate [VO3] chain along a, similar to that in the structure of rossite. The chains are linked via bonds to Ca atoms, which also bond to H2O groups, yielding CaO3(H2O)6 polyhedra. The Ca polyhedra form a chain along b. Each of the two symmetrically independent VO5 polyhedra has two short vanadyl bonds and three long equatorial bonds. Calciodelrioite and delrioite are isostructural and are the endmembers of the series Ca(VO3)2(H2O)4–Sr(VO3)2(H2O)4. Calciodelrioite is dimorphous with rossite, which has a similar structure; however, the smaller 8-coordinate Ca site in rossite does not accommodate Sr.

Tapiaite, Ca5Al2(AsO4)4(OH)4·12H2O, a new mineral from the Jote mine, Tierra Amarilla, Chile

2015 ◽  
Vol 79 (2) ◽  
pp. 345-354 ◽  
Author(s):  
Anthony R. Kampf ◽  
Stuart J. Mills ◽  
Barbara P. Nash ◽  
Maurizio Dini ◽  
Arturo A. Molina Donoso
Keyword(s):  
Empirical Formula ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
Interlayer Region ◽  
Mohs Hardness ◽  
Thick Layers

AbstractTapiaite (IMA2014-024), Ca5Al2(AsO4)4(OH)4·12H2O, is a new mineral from the Jote mine, Tierra Amarilla, Copiapó Province, Atacama, Chile. The mineral is a late-stage, low-temperature, secondary mineral occurring with conichalcite, joteite, mansfieldite, pharmacoalumite, pharmacosiderite and scorodite in narrow seams and vughs in the oxidized upper portion of a hydrothermal sulfide vein hosted by volcanoclastic rocks. Crystals occur as colourless blades, flattened on {101} and elongated and striated along [010], up to ∼0.5 mm long, and exhibiting the forms {101}, {101} and {111}. The blades are commonly intergrown in subparallel bundles and less commonly in sprays. The mineral is transparent and has a white streak and vitreous lustre. The Mohs hardness is estimated to be between 2 and 3, the tenacity is brittle, and the fracture is splintery. It has two perfect cleavages on {101} and {101}. The calculated density based on the empirical formula is 2.681 g cm–3. It is optically biaxial (+) with α = 1.579(1), β = 1.588(1), γ = 1.610(1) (white light), 2Vmeas = 66(2)° and 2Vcalc = 66°. The mineral exhibits no dispersion. The optical orientation is X ≈ [101]; Y = b, Z ≈ [101]. The electron-microprobe analyses (average of five) provided: Na2O 0.09, CaO 24.96, CuO 0.73, Al2O3 10.08, Fe2O3 0.19, As2O5 40.98, Sb2O5 0.09, H2 O 23.46 (structure), total 100.58 wt.%. In terms of the structure, the empirical formula (based on 32 O a.p.f.u.) is (Ca4.83Cu0.102+Na0.03)Σ4.96(Al2.14Fe0.033+)Σ2.17[(As3.875+Sb0.015+)Σ3.88O16][(OH)3.76(H2O)0.24]Σ4(H2O)10·2H2O. The mineral is easily soluble in RT dilute HCl. Tapiaite is monoclinic, P21/n, with unit-cell parameters a = 16.016(1), b = 5.7781(3), c = 16.341(1) Å, β = 116.704(8)°, V = 1350.9(2) Å3 and Z = 2. The eight strongest lines in the powder X-ray diffraction pattern are [dobs Å(I)(hkl)]: 13.91(100)(101), 7.23(17)(200,002), 5.39(22)(110,011), 4.64(33)(112,211,303), 3.952(42)(113,311,213), 3.290(35)(214,412,114,411), 2.823(39)(303,315) and 2.753(15)(513,115,121,511). The structure of tapiaite (R1 = 5.37% for 1733 Fo > 4σF) contains Al(AsO4)(OH)2 chains of octahedra and tetrahedra that are topologically identical to the chain in the structure of linarite. CaO8 polyhedra condense to the chains, forming columns, which are decorated with additional peripheral AsO4 tetrahedra. The CaO8 polyhedra in adjacent columns link to one another by corner-sharing to form thick layers parallel to {101} and the peripheral AsO4 tetrahedra link to CaO6 octahedra in the interlayer region, resulting in a framework structure.

scholarly journals Parisite-(La), ideally CaLa2(CO3)3F2, a new mineral from Novo Horizonte, Bahia, Brazil

2018 ◽  
Vol 82 (1) ◽  
pp. 133-144 ◽  
Author(s):  
Luiz A. D. Menezes Filho ◽  
Mario L. S. C. Chaves ◽  
Nikita V. Chukanov ◽  
Daniel Atencio ◽  
Ricardo Scholz ◽  
...  
Keyword(s):  
Single Crystal ◽  
Ir Spectrum ◽  
Empirical Formula ◽  
New Mineral ◽  
Formula Unit ◽  
Calculated Density ◽  
Oh Groups ◽  
Space Group ◽  
X Ray ◽  
Mohs Hardness

ABSTRACTParisite-(La) (IMA2016-031), ideally CaLa2(CO3)3F2, occurs in a hydrothermal vein crosscutting a metarhyolite of the Rio dos Remédios Group, at the Mula mine, Tapera village, Novo Horizonte county, Bahia, Brazil, associated with hematite, rutile, almeidaite, fluocerite-(Ce), brockite, monazite-(La), rhabdophane-(La) and bastnäsite-(La). Parisite-(La) occurs as residual nuclei (up to 5 mm) in steep doubly-terminated pseudo-hexagonal pyramidal crystals (up to 8.2 cm). Parisite-(La) is transparent, yellow-green to white, with a white streak and displays a vitreous (when yellow-green) to dull (when white) lustre. Cleavage is distinct on pseudo-{001}; fracture is laminated, conchoidal, or uneven. The Mohs hardness is 4 to 5, and it is brittle. Calculated density is 4.273 g cm−3. Parisite-(La) is pseudo-uniaxial (+), ω = 1.670(2) and ε = 1.782(5) (589 nm). The empirical formula normalized on the basis of 11 (O + F) atoms per formula unit (apfu) is Ca0.98(La0.83Nd0.51Ce0.37Pr0.16Sm0.04Y0.03)Σ1.94C3.03O8.91F2.09. The IR spectrum confirms the absence of OH groups. Single-crystal X-ray studies gave the following results: monoclinic (pseudo-trigonal), space group: C2, Cm, or C2/m, a = 12.356(1) Å, b = 7.1368(7) Å, c = 28.299(3) Å, β = 98.342(4)°, V = 2469.1(4) Å3 and Z = 12. Parisite-(La) is the La-dominant analogue of parisite-(Ce).

Pseudomeisserite-(NH4), a new mineral with a novel uranyl-sulfate linkage from the Blue Lizard mine, San Juan County, Utah, USA

2020 ◽  
Vol 84 (3) ◽  
pp. 435-443
Author(s):  
Anthony R. Kampf ◽  
Travis A. Olds ◽  
Jakub Plášil ◽  
Barbara P. Nash ◽  
Joe Marty
Keyword(s):  
New Mineral ◽  
San Juan ◽  
Optical Orientation ◽  
Uranyl Sulfate ◽  
X Ray ◽  
Pale Yellow ◽  
Light Yellow ◽  
Perfect Cleavage ◽  
Mohs Hardness ◽  
San Juan County

AbstractThe new mineral pseudomeisserite-(NH4) (IMA2018-166), (NH4,K)2Na4[(UO2)2(SO4)5]⋅4H2O, was found in the Blue Lizard mine, San Juan County, Utah, USA, where it occurs as light yellow prisms in a secondary assemblage with belakovskiite, blödite, changoite, ferrinatrite, gypsum, ivsite, metavoltine and tamarugite. The streak is very pale yellow and the fluorescence is bright lime green under 405 nm ultraviolet light. Crystals are transparent with vitreous lustre. The tenacity is brittle, the Mohs hardness is 2½, the fracture is curved or conchoidal and there is one perfect cleavage on {100}. The mineral is easily soluble in H2O and has a measured density of 3.22(2) g⋅cm–3. Pseudomeisserite-(NH4) is optically biaxial (–) with α = 1.536(2), β = 1.559(2) and γ = 1.565(2) (white light); 2Vmeas. = 53(1)°; dispersion is r > v, distinct; pleochroism: X colourless, Y light yellow and Z pale yellow (X < Z < Y); optical orientation: Z = b, Y ∧ c = 33° in obtuse β). Electron microprobe analyses (WDS mode) provided (NH4)1.49K0.60Na3.87U2.00S5.04O28H7.78. The five strongest X-ray powder diffraction lines are [dobs, Å(I)(hkl)]: 12.69(76)(100), 6.83(84)(012,102), 6.01(100)($\bar{2}$02), 3.959(67)($\bar{2}$21,$\bar{2}$14,$\bar{1}$23) and 3.135(76)($\bar{2}$06,223,$\bar{1}$16). Pseudomeisserite-(NH4) is monoclinic, P21/c, a = 13.1010(3), b = 10.0948(2), c = 19.4945(14) Å, β = 104.285(7)°, V = 2498.5(2) Å3 and Z = 4. The structural unit in the structure (R1 = 0.0254 for 3837 I > 2σI reflections) is a novel [(UO2)2(SO4)5]6– uranyl-sulfate band.

Bassoite, SrV3O7·4H2O, a new mineral from Molinello mine, Val Graveglia, eastern Liguria, Italy

2011 ◽  
Vol 75 (5) ◽  
pp. 2677-2686 ◽  
Author(s):  
L. Bindi ◽  
C. Carbone ◽  
R. Cabella ◽  
G. Lucchetti
Keyword(s):  
Structure Refinement ◽  
Full Professor ◽  
New Mineral ◽  
Monoclinic Space Group ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
Mohs Hardness ◽  
Dark Green ◽  
The University

AbstractBassoite, ideally SrV3O7·4H2O, is a new mineral from the Molinello manganese mine, Val Graveglia. eastern Liguria, northern Apennines, Italy. It occurs as black euhedral to subhedral grains up to 400 urn across, closely associated with rhodonite, quartz and braunite. Bassoite is opaque with a sub-metallic lustre and a black streak. It is brittle and neither fracture nor cleavage was observed; the Vickers micro-hardness (VHN100) is 150 kg/mm (range 142—165; corresponding to a Mohs hardness of 4—41/2). The calculated density is 2.940 g/cm3 (on the basis of the empirical formula and X-ray single-crystal data). Bassoite is weakly bireflectant and very weakly pleochroic from grey to a dark green. Internal reflections are absent. The mineral is anisotropic, without characteristic rotation tints. Reflectance percentages (Rmin and Rmax) for the four standard COM wavelengths are 18.5%, 19.0% (471.1 nm); 17.2%, 17.8% (548.3 nm); 16.8%, 17.5% (586.6 nm) and 16.2%, 16.8% (652.3 nm), respectively.Bassoite is monoclinic, space group P21/m, with unit-cell parameters: a = 5.313(3) Å, b = 10.495(3) Å, c = 8.568(4) Å, β = 91.14(5)°, V= 477.7(4) Å3, a:b:c = 0.506:1:0.816, and Z = 2. The crystal structure was refined to R1 = 0.0209 for 1148 reflections with Fo > 4σ(Fo) and it consists of layers of VO5 pyramids (with vanadium in the tetravalent state) pointing up and down alternately with Sr between the layers (in nine-fold coordination). The nine most intense X-ray powder-diffraction lines [d in Å (I/I0) (hkt)] are: 8.5663 (100) (001); 6.6363 (14) (011); 3.4399 (14) (1̄21); 3.4049 (17) (121); 2.8339 (15) (1̄22); 2.7949 (11) (122); 2.6550 (15) (200); 2.6237 (11) (040) and 1.8666 (15) (240). Electron microprobe analyses produce a chemical formula (Sr0.97Ca0.02Na0.01)V3.00O74H20, on the basis of 2(Sr+Ca+Na) = 1, taking the results of the structure refinement into account. The presence of water molecules was confirmed by micro-Raman spectroscopy. The name honours Riccardo Basso (b. 1947), full professor of Mineralogy and Crystallography at the University of Genova. The new mineral and mineral name have been approved by the Commission on New Minerals, Nomenclature and Classification, IMA (2011-028).

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