Müllerite, the Fe-analogue of backite from Otto Mountain, California, USA

2020 ◽  
Vol 58 (4) ◽  
pp. 413-419
Author(s):  
Stuart J. Mills ◽  
Anthony R. Kampf ◽  
Koichi Momma ◽  
Robert M. Housley ◽  
Joseph Marty
Keyword(s):  
Rietveld Analysis ◽  
Thin Plates ◽  
New Mineral ◽  
San Bernardino County ◽  
Unit Cell Parameters ◽  
Calculated Density ◽  
Cell Parameters ◽  
San Bernardino ◽  
Perfect Cleavage ◽  
Reddish Orange

ABSTRACT Müllerite (IMA2019–060) is a new mineral found at several workings on Otto Mountain, 2.5 km NW of Baker, San Bernardino County, California, USA. Müllerite occurs as hexagonal tablets and thin plates up to 0.2 mm across, intergrown ball-like clusters, and scattered flakes. Crystals are yellow, tending to reddish-orange, and have a pale-yellow streak and subadamantine to greasy luster. Crystals are brittle with an irregular fracture and have a hardness of ∼2 and perfect cleavage on {001}. The main forms observed are {100} and {001}. The calculated density is 5.812 g/cm3. The empirical formula (based on 7 O + Cl + I apfu) is Pb1.83Ag0.26Fe0.93Al0.03Cu0.02Te6+0.95O5.56Cl1.30I0.14; the endmember formula is Pb2Fe3+(Te6+O6)Cl. Müllerite is trigonal, space group P312, with the unit cell parameters a = 5.2040(5), c = 8.9654(12) Å, V = 210.23(3) Å3, and Z = 1. The crystal structure of müllerite was refined using Rietveld analysis and converged to Rwp = 4.861%, S = 0.1873, RB = 1.800%, and RF = 0.691%. Müllerite is the Fe-analogue of backite, Pb2Al3+(Te6+O6)Cl.

Wesselsite, SrCu[Si4O10], a further new gillespite-group mineral from the Kalahari Manganese Field, South Africa

1996 ◽  
Vol 60 (402) ◽  
pp. 795-798 ◽  
Author(s):  
G. Giester ◽  
B. Rieck
Keyword(s):  
South Africa ◽  
New Mineral ◽  
Solid Solution Series ◽  
Blue Colour ◽  
Unit Cell Parameters ◽  
Calculated Density ◽  
Light Blue ◽  
Cell Parameters ◽  
New Mineral Species ◽  
Perfect Cleavage

AbstractWesselsite, SrCu[Si4O10], is a new mineral species from the Wessels mine, Kalahari Manganese Field, South Africa, and it belongs to the gillespite group. Wesselsite is tetragonal, space group P4/ncc; the unit cell parameters, refined from Gandolfi film data, are a = 7.366(1), c = 15.574(3) Å V = 845.01 Å3. The strongest lines are (dobs/lobs/hkl) (7.79/35/002), (4.33/20/112), (3.89/20/004), (3.44/40/104), (3.33/100/202), (3.12/55/114), (3.03/50/212), (2.68/25/204), (2.61/30/220) and (2.32/30/116). Wesselsite is associated with hennomartinite, embedded in a matrix of sugilite, xonotlite, quartz and pectolite. Microprobe analyses of 111 samples show that it is the end-member of a solid solution series with effenbergerite, BaCu[Si4O10], with substitutions of Sr by Ba up to 50 mol.%. Wesselsite forms tiny subhedral plates in sizes not exceeding 50 × 50 × 5 µm, arranged in clusters of up to 200 µm. It shows a perfect cleavage parallel to {001}, has blue colour, white to light blue streak, and is uniaxial negative with ω = 1.630(2), ε = 1.590(5), strongly pleochroic from blue (ω) to pale blue (ε). The calculated density is 3.32 g cm−3, the measured density is 3.2(1) g cm−3.

Deveroite-(Ce): a new REE-oxalate from Mount Cervandone, Devero Valley, Western-Central Alps, Italy

2013 ◽  
Vol 77 (7) ◽  
pp. 3019-3026 ◽  
Author(s):  
A. Guastoni ◽  
F. Nestola ◽  
P. Gentile ◽  
F. Zorzi ◽  
M. Alvaro ◽  
...  
Keyword(s):  
Structural Data ◽  
New Mineral ◽  
Central Alps ◽  
Chemical Formula ◽  
Unit Cell Parameters ◽  
Calculated Density ◽  
Cell Parameters ◽  
Natural Park ◽  
Extinction Angle ◽  
Perfect Cleavage

AbstractDeveroite-(Ce), ideally Ce2(C2O4)3·10H2O, is a new mineral (IMA 2013-003) found in the alpine fissures of Mount Cervandone, overlooking the Devero Valley, Piedmont, Italy. It occurs as sprays of colourless elongated tabular, acicular prisms only on cervandonite-(Ce). It has a white streak, a vitreous lustre, is not fluorescent and has a hardness of 2–2.5 (Mohs' scale). The tenacity is brittle and the crystals have a perfect cleavage along {010}. The calculated density is 2.352 g/cm3. Deveroite-(Ce) is biaxial (–) with 2V of ∼77°, is not pleochroic and the extinction angle (β ∧ c) is ∼27°. No twinning was observed. Electron microprobe analyses gave the following chemical formula: (Ce1.01Nd0.33La0.32Pr0.11Y0.11Sm0.01Pb0.04U0.03Th0.01Ca0.04)2.01(C2O4)2.99·9.99H2O. Although synchrotron radiation was not used to solve the structure of deveroite-(Ce) the extremely small size of the sample (13 μm × 3 μm × 1 μm) did not allow us to obtain reliable structural data. However, it was possible to determine the space group (monoclinic, P21/c) and the unit-cell parameters, which are: a = 11.240(8) Å, b = 9.635(11) Å, c = 10.339(12) Å, β = 114.41(10)°, V = 1019.6 Å3. The strongest lines in the powder diffraction pattern [d in Å (I)(hkl)] are: 10.266(100)(100); 4.816(35.26)(21); 3.415(27.83)(300); 5.125(24.70)(200); and 4.988(22.98)(111). Deveroite-(Ce) is named in recognition of Devero valley and Devero Natural Park.

scholarly journals Tazzoliite: a new mineral with a pyrochlore-related structure from the Euganei Hills, Padova, Italy

2012 ◽  
Vol 76 (4) ◽  
pp. 827-838 ◽  
Author(s):  
F. Cámara ◽  
F. Nestola ◽  
L. Bindi ◽  
A. Guastoni ◽  
F. Zorzi ◽  
...  
Keyword(s):  
Pyrochlore Structure ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Orthorhombic Space Group ◽  
Calculated Density ◽  
Oh Groups ◽  
X Ray ◽  
Cell Parameters ◽  
Perfect Cleavage

AbstractTazzoliite, ideally Ba2CaSr0.5Na0.5Ti2Nb3SiO17[PO2(OH)2]0.5, is a new mineral (IMA 2011-018) from Monte delle Basse, Euganei Hills, Galzignano Terme, Padova, Italy. It occurs as lamellar pale orange crystals, which are typically a few m m thick and up to 0.4 mm long, closely associated with a diopsidic pyroxene and titanite. Tazzoliite is transparent. It has a white streak, a pearly lustre, is not fluorescent and has a hardness of 6 (Mohs' scale). The tenacity is brittle and the crystals have a perfect cleavage along {010}. The calculated density is 4.517 g cm–3. Tazzoliite is biaxial (–) with 2Vmeas of ~50º, it is not pleochroic and the average refractive index is 2.04. No twinning was observed. Electronmicroprobe analyses gave the following chemical formula: (Ba1.93Ca1.20Sr0.52Na0.25Fe0.102+)Σ4 (Nb2.88Ti2.05Ta0.07Zr0.01V0.015+)Σ5.02SiO17[(P0.13Si0.12S0.07)Σ0.32O0.66(OH)0.66][F0.09(OH)0.23]Σ0.32.Tazzoliite is orthorhombic, space group Fmmm, with unit-cell parameters a = 7.4116(3), b = 20.0632(8), c = 21.4402(8) Å, V = 3188.2(2) Å3 and Z = 8. The crystal structure, obtained from single-crystal X-ray diffraction data, was refined to R1(F2) = 0.063. It consists of a framework of Nb(Ti) octahedra and BaO7 polyhedra sharing apexes or edges, and Si tetrahedra sharing apexes with Nb(Ti) octahedra and BaO7 polyhedra. The structure, which is related to the pyrochlore structure, contains three Nb(Ti) octahedra: two are Nb dominant and one is Ti dominant. Chains of A2O8 polyhedra [A2 being occupied by Sr(Ca, Fe)] extend along [100] and are surrounded by Nb octahedra. Channels formed by six Nb(Ti) octahedra and two tetrahedra, or four A1O8(OH) polyhedra (A1 being occupied by Ba), alternate along [100]. The channels are partially occupied by [PO2(OH)2] in two possible mutually exclusive positions, alternating with fully occupied A3O7 polyhedral pairs [A3 being occupied by Ca(Na)]. The seven strongest X-ray powder diffraction lines [d in Å (I/I0) (hkl)] are: 3.66 (60) (044), 3.16 (30) (153), 3.05 (100) (204), 2.98 (25) (240), 2.84 (50) (064), 1.85 (25) (400) and 1.82 (25) (268). Raman spectra of tazzoliite were collected in the range 150–3700 cm–1 and confirm the presence of OH groups. Tazzoliite is named in honour of Vittorio Tazzoli in recognition of his contributions to the fields of mineralogy and crystallography.

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.

Arrheniusite-(Ce), CaMg[(Ce7Y3)Ca5](SiO4)3(Si3B3O18)(AsO4)(BO3)F11, a New Member of the Vicanite Group, from the Östanmossa Mine, Norberg, Sweden

2021 ◽  
Author(s):  
Dan Holtstam ◽  
Luca Bindi ◽  
Paola Bonazzi ◽  
Hans-Jürgen Förster ◽  
Ulf B. Andersson
Keyword(s):  
Structure Refinement ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Calculated Density ◽  
Epma Data ◽  
X Ray ◽  
Cell Parameters ◽  
Greenish Yellow ◽  
The Ideal

ABSTRACT Arrheniusite-(Ce) is a new mineral (IMA 2019-086) from the Östanmossa mine, one of the Bastnäs-type deposits in the Bergslagen ore region, Sweden. It occurs in a metasomatic F-rich skarn, associated with dolomite, tremolite, talc, magnetite, calcite, pyrite, dollaseite-(Ce), parisite-(Ce), bastnäsite-(Ce), fluorbritholite-(Ce), and gadolinite-(Nd). Arrheniusite-(Ce) forms anhedral, greenish-yellow translucent grains, exceptionally up to 0.8 mm in diameter. It is optically uniaxial (–), with ω = 1.750(5), ε = 1.725(5), and non-pleochroic in thin section. The calculated density is 4.78(1) g/cm3. Arrheniusite-(Ce) is trigonal, space group R3m, with unit-cell parameters a = 10.8082(3) Å, c = 27.5196(9) Å, and V = 2784.07(14) Å3 for Z = 3. The crystal structure was refined from X-ray diffraction data to R1 = 3.85% for 2286 observed reflections [Fo > 4σ(Fo)]. The empirical formula for the fragment used for the structural study, based on EPMA data and results from the structure refinement, is: (Ca0.65As3+0.35)Σ1(Mg0.57Fe2+0.30As5+0.10Al0.03)Σ1[(Ce2.24Nd2.13La0.86Gd0.74Sm0.71Pr0.37)Σ7.05(Y2.76Dy0.26Er0.11Tb0.08Tm0.01Ho0.04Yb0.01)Σ3.27Ca4.14]Σ14.46(SiO4)3[(Si3.26B2.74)Σ6O17.31F0.69][(As5+0.65Si0.22P0.13)Σ1O4](B0.77O3)F11; the ideal formula obtained is CaMg[(Ce7Y3)Ca5](SiO4)3(Si3B3O18)(AsO4)(BO3)F11. Arrheniusite-(Ce) belongs to the vicanite group of minerals and is distinct from other isostructural members mainly by having a Mg-dominant, octahedrally coordinated site (M6); it can be considered a Mg-As analog to hundholmenite-(Y). The threefold coordinated T5 site is partly occupied by B, like in laptevite-(Ce) and vicanite-(Ce). The mineral name honors C.A. Arrhenius (1757–1824), a Swedish officer and chemist, who first discovered gadolinite-(Y) from the famous Ytterby pegmatite quarry.

Liudongshengite, Zn4Cr2(OH)12(CO3)·3H2O, a new mineral of the hydrotalcite supergroup, from the 79 mine, Gila County, Arizona, USA

2021 ◽  
Vol 59 (4) ◽  
pp. 763-769
Author(s):  
Hexiong Yang ◽  
Ronald B. Gibbs ◽  
Cody Schwenk ◽  
Xiande Xie ◽  
Xiangping Gu ◽  
...  
Keyword(s):  
Unit Cell ◽  
New Mineral ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
New Mineral Species ◽  
General Chemical ◽  
Perfect Cleavage ◽  
Mohs Hardness ◽  
Trivalent Cations ◽  
Positively Charged

ABSTRACT A new mineral species, liudongshengite, ideally Zn4Cr2(OH)12(CO3)·3H2O, has been found in the 79 mine, Gila County, Arizona, USA. It occurs as micaceous aggregates or hexagonal platy crystals (up to 0.10 × 0.10 × 0.01 mm). The mineral is pinkish and transparent with white streak and vitreous luster. It is brittle and has a Mohs hardness of ∼1.5, with perfect cleavage on (001). No twinning or parting is observed macroscopically. The measured and calculated densities are 2.95 (3) and 3.00 g/cm3, respectively. Optically, liudongshengite is uniaxial (−), with ω = 1.720 (8), ε = 1.660 (7) (white light). An electron microprobe analysis, combined with the carbon content measured using an elemental combustion system equipped with mass spectrometry, yielded the empirical formula (Zn3.25Mg0.17Cr2.58)Σ6.00(OH)12(CO3)1.29·3H2O, based on (M2+ + M3+) = 6 apfu, where M2+ and M3+ are divalent and trivalent cations, respectively. Liudongshengite belongs to the quintinite group within the hydrotalcite supergroup and is the Cr-analogue of zaccagnaite-3R, Zn4Al2(OH)12(CO3)·3H2O. It is trigonal, with space group Rm and unit-cell parameters a = 3.1111(4), c = 22.682(3) Å, and V = 190.12(4) Å3. The crystal structure of liudongshengite is composed of positively charged brucite-like layers, [M2+1–xM3+x(OH)2]x+, alternating with negatively charged layers of (CO3)2–·3H2O. Compared to other minerals in the quintinite group, liudongshengite is remarkably enriched in M3+, with an M2+:M3+ ratio of 1.33:1. Like zaccagnaite-3R and many other hydrotalcite-type minerals, liudongshengite may also possess polytypes, as a series of synthetic hydrotalcite-type compounds with a general chemical formula [Zn4Cr2(OH)12]X2·4H2O, where X = Cl–, NO3–, or ½ SO42–, but with unit-cell parameters different from those for liudongshengite, have been reported previously.

scholarly journals Langhofite, Pb2(OH)[WO4(OH)], a new mineral from Långban, Sweden

2020 ◽  
Vol 84 (3) ◽  
pp. 381-389
Author(s):  
Dan Holtstam ◽  
Fernando Cámara ◽  
Andreas Karlsson
Keyword(s):  
New Mineral ◽  
Calculated Density ◽  
Triclinic Space Group ◽  
Oh Groups ◽  
International Mineralogical Association ◽  
Cell Parameters ◽  
Discovery Sample ◽  
Vibration Spectroscopy ◽  
Perfect Cleavage ◽  
Mohs Hardness

AbstractLanghofite, ideally Pb2(OH)[WO4(OH)], is a new mineral from the Långban mine, Värmland, Sweden. The mineral and its name were approved by the International Mineralogical Association Commission on New Minerals, Nomenclature and Classification (IMA2019-005). It occurs in a small vug in hematite–pyroxene skarn associated with calcite, baryte, fluorapatite, mimetite and minor sulfide minerals. Langhofite is triclinic, space group P$\bar{1}$, and unit-cell parameters a = 6.6154(1) Å, b = 7.0766(1) Å, c = 7.3296(1) Å, α = 118.175(2)°, β = 94.451(1)°, γ = 101.146(1)° and V = 291.06(1) Å3 for Z = 2. The seven strongest Bragg peaks from powder X-ray diffractometry are [dobs, Å (I)(hkl)]: 6.04(24)(010), 3.26(22)(11$\bar{2}$), 3.181(19)(200), 3.079(24)(1$\bar{1}$2), 3.016(100)(020), 2.054(20)(3$\bar{1}$1) and 2.050(18)(13$\bar{2}$). Langhofite occurs as euhedral crystals up to 4 mm, elongated along the a axis, with lengthwise striation. Mohs hardness is ca. 2½, based on VHN25 data obtained in the range 130–192. The mineral is brittle, with perfect {010} and {100} cleavages. The calculated density based on the ideal formula is 7.95(1) g⋅cm–3. Langhofite is colourless to white (non-pleochroic) and transparent, with a white streak and adamantine lustre. Reflectance curves show normal dispersion, with maximum values 15.7–13.4% within 400–700 nm. Electron microprobe analyses yield only the metals Pb and W above the detection level. The presence of OH-groups is demonstrated with vibration spectroscopy, from band maxima present at ~3470 and 3330 cm–1. A distinct Raman peak at ca. 862 cm–1 is related to symmetric W–oxygen stretching vibrations. The crystal structure is novel and was refined to R = 1.6%. It contains [W2O8(OH)2]6– edge-sharing dimers (with highly distorted WO6-octahedra) forming chains along [101] with [(OH)2Pb4]6+ dimers formed by (OH)Pb3 triangles. Chains configure (010) layers linked along [010] by long and weak Pb–O bonds, thus explaining the observed perfect cleavage on {010}. The mineral is named for curator Jörgen Langhof (b. 1965), who collected the discovery sample.

Tangdanite, a new mineral species from the Yunnan Province, China and the discreditation of ‘clinotyrolite’

2014 ◽  
Vol 78 (3) ◽  
pp. 559-569 ◽  
Author(s):  
Ma Zhesheng ◽  
Li Guowu ◽  
N. V. Chukanov ◽  
G. Poirier ◽  
Shi Nicheng
Keyword(s):  
Yunnan Province ◽  
Short Wave ◽  
Mineral Species ◽  
Sulfide Deposit ◽  
New Mineral ◽  
Mining District ◽  
Calculated Density ◽  
Cell Parameters ◽  
New Mineral Species ◽  
Perfect Cleavage

AbstractTangdanite, ideally Ca2Cu9(AsO4)4(SO4)0.5(OH)9·9H2O and monoclinic, is a new mineral species (IMA No. 2011-096) occurring in the Tangdan and Nanniping mines, southeast Dongchuan copper mining district, Dongchuan County, Kunming City Prefecture, Yunnan Province, P. R. China (26°11’N 103°51’E). The mineral is found in the oxidized zone (gossan) of an As-bearing Cu sulfide deposit and is clearly of supergene origin. Associated minerals are chalcopyrite, bornite, chalcocite, covellite, tennantite, enargite, cuprite, malachite, azurite, copper and brochantite. Crystals form radiating or foliated aggregates of flaky crystals up to 3 mm, flattened parallel to (100) and elongated along [001]. It is emerald green with a light green streak, translucent and has a pearly to silky lustre. It is sectile having perfect cleavage on {100} although neither parting nor fracture was observed. No fluorescence in long- or short-wave ultraviolet radiation was observed. The hardness is VHN50 42.0−43.6, mean 42.8 kg mm−2 (2−2½ on the Mohs scale). The density measured by pycnometry is 3.22 g cm−3 (Ma et al., 1980). The calculated density from the empirical chemical formula is 3.32 g cm−3. The compatability index gives 1 − (Kp/Kc) = −0.041 (good). The empirical formula (based on 36 O a.p.f.u) of tangdanite is Ca2.05Cu9.08(As1.03O4)4(S0.63O4)0.5(OH)9·9H2.04O. The simplified formula is Ca2Cu9(AsO4)4(SO4)0.5(OH)9·9H2O. The strongest five reflections in the X-ray powder-diffraction pattern [d in Å(I) (hkl)] are: 4.782(100) ( 1 1), 4.333(71) (6 0 2), 5.263(54) ( 0 2), 3.949(47) (8 0 2) and 2.976(46) ( 1 1). The unit-cell parameters are a = 54.490(9), b = 5.5685(9), c = 10.4690(17) Å, β = 96.294(3)o, V = 3157.4(9) Å3, Z = 4. Its structure was solved and refined in space group C2/c, with R = 0.110.

A new mineral, zincolibethenite, CuZnPO4OH, a stoichiometric species of specific site occupancy

2005 ◽  
Vol 69 (2) ◽  
pp. 145-153 ◽  
Author(s):  
R. S. W. Braithwaite ◽  
R. G. Pritchard ◽  
W. H. Paar ◽  
R. A. D. Pattrick
Keyword(s):  
Atmospheric Pressure ◽  
Site Occupancy ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Cation Site ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
Jahn Teller

AbstractTiny green crystals from Kabwe, Zambia, associated with hopeite and tarbuttite (and probably first recorded in 1908 but never adequately characterized because of their scarcity) have been studied by X-ray diffraction, microchemical and electron probe microanalysis, infrared spectroscopy, and synthesis experiments. They are shown to be orthorhombic, stoichiometric CuZnPO4OH, of species rank, forming the end-member of a solid-solution series to libethenite, Cu2PO4OH, and are named zincolibethenite. The libethenite structure is unwilling to accommodate any more Zn substituting for Cu at atmospheric pressure, syntheses using Zn-rich solutions precipitating a mixture of zincolibethenite with hopeite, Zn3(PO4)2.4H2O. Single-crystal X-ray data confirm that the Cu(II) occupies the Jahn-Teller distorted 6-coordinate cation site in the libethenite lattice, and the Zn(II) occupies the 5-coordinate site. The space group of zincolibethenite is Pnnm, the same as that of libethenite, with unit-cell parameters a = 8.326, b = 8.260, c = 5.877 Å , V = 404.5 Å 3, Z = 4, calculated density = 3.972 g/cm3 (libethenite has a = 8.076, b = 8.407, c = 5.898 Å , V = 400.44 Å 3, Z = 4, calculated density = 3.965 g/cm3). Zincolibethenite is biaxial negative, with 2Vα(calc.) of 49°, r<v, and α = 1.660, β = 1.705, and γ = 1.715 The mineral is named for its relationship to libethenite.

Leisingite, Cu(Mg,Cu,Fe,Zn)2Te6+O6·6H2O, a new mineral species from the Centennial Eureka mine, Juab County, Utah

1996 ◽  
Vol 60 (401) ◽  
pp. 653-657 ◽  
Author(s):  
Andrew C. Roberts ◽  
Lee A. Groat ◽  
Joel D. Grice ◽  
Robert A. Gault ◽  
Martin C. Jensen ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Infrared Absorption Spectrum ◽  
Thin Plates ◽  
New Mineral ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Pale Yellow ◽  
Orange Yellow ◽  
New Mineral Species

AbstractLeisingite, ideally Cu(Mg,Cu,Fe,Zn)2Te6+O6·6H2O, is hexagonal, P3 (143), with unit-cell parameters refined from powder data: a = 5.305(1), c = 9.693(6) Å, V = 236.2(2) Å3, c/a = 1.8271, Z = 1. The strongest six reflections of the X-ray powder-diffraction pattern [d in Å (I) (hkl)] are: 9.70 (100) (001), 4.834 (80) (002), 4.604 (60) (100), 2.655 (60) (110), 2.556 (70) (111) and 2.326 (70) (112). The mineral is found on the dumps of the Centennial Eureka mine, Juab County, Utah U.S.A. where it occurs as isolated, or rarely as clusters of, hexagonal-shaped very thin plates or foliated masses in small vugs of crumbly to drusy white to colourless quartz. Associated minerals are jensenite, cesbronite and hematite. Individual crystals are subhedral to euhedral and average less than 0.1 mm in size. Cleavage {001} perfect. Forms are: {001} major; {100}, {110} minute. The mineral is transparent to somewhat translucent, pale yellow to pale orange-yellow, with a pale yellow streak and an uneven fracture. Leisingite is vitreous with a somewhat satiny to frosted appearance, brittle to somewhat flexible and nonfluorescent; H(Mohs) 3–4; D(calc.) 3.41 for the idealized formula; uniaxial negative, ω = 1.803(3), ɛ = 1.581 (calc.). Averaged electron-microprobe analyses yielded CuO 24.71, FeO 6.86, MgO 6.19, ZnO 0.45, TeO3 36.94, H2O (calc.) [21.55], total [96.70] wt.%, leading to the empirical formula based on O = 12. The infrared absorption spectrum shows definite bands for structural H2O with an O-H stretching frequency centered at 3253 cm−1 and a H-O-H flexing frequency centered at 1670 cm−l. The mineral name honours Joseph F. Leising, Reno, Nevada, who helped collect the discovery specimens.

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