Hubbardite, a new magnesium uranyl-sulfate mineral closely related to zippeite

Iangreyite, ideally Ca2Al7(PO4)2(PO3OH)2(OH,F)15·8H2O, is a new mineral (IMA2009-087) from the Silver Coin mine, Nevada, USA and the Krásno ore district, Horní Slavkov, Czech Republic. At Silver Coin, iangreyite occurs as thin, colourless to white or cream, hexagonal tablets up to 0.4 mm in diameter and 0.02 mm thick associated with meurigite-Na, plumbogummite, kidwellite, lipscombite. strengite, chalcosiderite, wardite, leucophosphite, wavellite, goethite, barite, quartz and F-rich perhamite. At Krásno, white, yellowish or light pink iangreyite coatings consist of 0.3 mm wide clusters of minute and very thin intergrown tabular crystals with a maximum diameter of 0.2 mm. Individual iangreyite crystals are transparent with a vitreous lustre, while iangreyite clusters tend to be pearly and translucent. The estimated hardness is 3 on the Mohs scale, the fracture is irregular and the mineral is non-fluorescent under SW and LW ultraviolet light. Individual crystals are somewhat flexible and there is perfect cleavage on ﹛001﹜. The density (Silver Coin), measured by the sink-float method in an aqueous solution of sodium polytungstate, is 2.46(3) g/cm3, while the calculated density is 2.451 g/cm3. Crystals from Silver Coin are uniaxial (+), with the indices of refraction: ε = 1.544(2) and s = 1.554(2), measured in white light, and are non-pleochroic. The empirical formula for iangreyite from Silver Coin (calculated on the basis of 39 anions per formula unit) is: Ca1.42K0.22Na0.09Ba0.03 Sr0.01Al6.51Mg0.09Fe0.02Cu0.01Zn0.01P3.81F5.24H30.21O33.76, while the empirical formula from Krásno is: Ca2.15K0.10Na0.01Ba0.02Sr0.12Al6.28Mg0.01Fe0.12Cu0.08Zn0.01P3.64Si0.43F4.65H29.62O34.35. Iangreyite is trigonal, space group P321 and Z = 1, with the unit-cell parameters (Silver Coin): a = 6.988(1), c = 16.707(3) Å and V= 706.5(2) Å3 and (Krasno): a = 6.989(1), c = 16.782(4) Å and V = 709.8(2) Å3. The structure of iangreyite, modelled from powder data, consists of blocks of the crandallite-type structure that are interconnected along c via corner-sharing of crandallite-block PO4 tetrahedra with A1O2(OH)3 bipyramids. This linkage generates large channels along [110] bounded by 10-member rings of octahedra, tetrahedra and trigonal biyramids, that are occupied by Ca and water molecules.

Szilagyiite (IMA 2024-063), NaCa 3 (UO 2 )(CO 3 ) 3 (SeO 3 )F(H 2 O) 6 , is a new uranyl-carbonate-selenite mineral from the Pickett Corral mine, Montrose County, Colorado, USA.The new mineral occurs on sandstone and asphaltite matrix in close association with ferroselite, andersonite, schrckingerite, magselite, and an unidentified Na-Ca-uranyl carbonate--selenite-sulfate.Szilagyiite is trigonal, space group R3c (#161), with unit cell parameters a = 9.6542(9), c = 33.465(5), V = 2701.2(6) 3 and Z = 6.Crystals occur as dense yellow-green rosettes up to 1 mm wide and individual tablets up to ~200 m.Szilagyiite crystals are predominantly tabular on {001} and exhibit {001}, {00-1}, {102}, and {0-1-2} forms, with frequent twinning by inversion and perfect {001} cleavage.It has a pale yellow-green streak and fluoresces dimly green under longwave UV and 405 nm illumination, but has no apparent fluorescence under SWUV.Crystals are transparent with vitreous luster and exhibit a brittle, uneven fracture, with a Mohs hardness between 2-3.The calculated density based on the empirical formula is 3.17 g/cm 3 , and 3.16(2) g/cm 3 as measured by flotation in a mixture of diiodomethane and toluene.The mineral is optically uniaxial (-), with = 1.628( 2), = 1.538(2) measured in white light.It is pleochroic: O yellow, E colorless; O > E. The empirical formula is Na 0.76 Ca 3.11 (UO 2 )(CO 3 ) 3 (Se 1.16 O 3 )F 0.82 O 20.18 H 13.19 based on 21 O + F, U = 1, with C = 3 apfu based on the structure and H set to achieve charge balance.The eight strongest powder X-ray diffraction lines are [d obs (I)(hkl)]: 5.916(100)(104), 4.836(58)(110), 3.744(77)(018), 3.125(33)(211,122), 2.960(60)(214), 2.795(62)(300), 1.828(40)(410) and 1.744(35)(238,146).The structure of szilagyiite (R 1 = 0.0314 for 2335 reflections with I > 2I) is based on infinite sheets built from 3 major components: distorted cubane-like [(SeO 3 ) Ca 3 (F,OH)(H 2 O) 3 ] units, NaO 4 (H 2 O) 3 monocapped trigonal antiprisms, and hexagonal bipyramidal uranyl tricarbonate cluster units, [UO 2 (CO 3 ) 3 ].The sheets are cross-linked by a thin layer of hydrogen bonds formed between interlayer H 2 O bound to Na, with F/OH, and O in the sheets.

The new mineral zincostottite (IMA2024-024), ZnGe(OH)6, was found on specimens from the Tsumeb mine, Tsumeb, Namibia, where it is a secondary oxidation-zone mineral. It occurs as heavily etched remnants of equant or tabular crystals, up to ∼1 mm in diameter. Crystals are colourless and transparent, with vitreous to subadamantine lustre and a white streak. The mineral is brittle with irregular stepped fracture. The Mohs hardness is ∼4.5. Cleavage is good on {100} and poor on {001}. The calculated density is 3.834 g·cm–3. Optically, zincostottite is uniaxial (–) with ω = 1.785(5) and ε = 1.765(5) (white light). The empirical formula is (Zn0.77Fe3+0.23)Σ1.00Ge1.00O6H5.77. Zincostottite is tetragonal, space group P42/n, with cell parameters: a = 7.4522(18), c = 7.4000(8) Å, V = 411.0(2) Å3 and Z = 4. The crystal structure (R1 = 2.65% for 452 I > 2σ I reflections) is the same as that of stottite with Zn in place of Fe2+

Meisserite (IMA2013-039), Na5(UO2)(SO4)3(SO3OH)(H2O), is a new uranyl sulfate mineral from the Blue Lizard mine, San Juan County, Utah (USA). It is named in honour of the prominent Swiss mineralogist Nicolas Meisser. The new mineral was found in a sandstone matrix and is associated with chalcanthite, copiapite, ferrinatrite, gypsum, johannite and another new Na-bearing uranyl sulfate, belakovskiite (IMA2013-075). Meisserite is a secondary mineral formed by the post-mining weathering of uraninite. The mineral is triclinic,P,a= 5.32317(10),b= 11.5105(2),c= 13.5562(10) Å, α = 102.864(7)°, β = 97.414(7)°, γ = 91.461(6)°,V= 801.74(6) Å3, andZ= 2. Crystals are prisms elongated on [100], up to 0.3 mm long, exhibiting the forms {010} and {001}. Meisserite is pale green to yellowish green, translucent to transparent and has a very pale yellow streak. It is brittle, with fair cleavage on {100} and {001}, and uneven fracture. The Mohs hardness is estimated at 2. Meisserite is somewhat hygroscopic and easily soluble in water. The calculated density based on the empirical formula is 3.208 g/cm3. Meisserite exhibits bright yellow green fluorescence under both long- and shortwave UV radiation. The mineral is optically biaxial (–), with α = 1.514(1), β = 1.546(1), γ = 1.557(1) (measured in white light). The measured 2V is 60(2)° and the calculated 2V is 60°. Dispersion isr > v, perceptible, and the optical orientation isX≈a,Z≈c*. The mineral is pleochroic, withX(colourless) <Y(pale yellow) ≈Z(pale greenish yellow). The empirical formula of meisserite (based on 19 O a.p.f.u.) is Na5.05(U0.94O2)(SO4)3[SO2.69(OH)1.31](H2O). The Raman spectrum is dominated by the symmetric stretching vibrations of UO22+, SO42–and also weaker O–H stretching vibrations. The eight strongest powder X-ray diffraction lines are [dobsin Å(hkl)Irel]: 13.15 (001) 81, 6.33 (02) 62, 5.64 (01,020) 52, 5.24 (100,012,01) 100, 4.67 (101) 68, 3.849 (1,102,022) 48, 3.614 (02,3) 41, and 3.293 (13,004) 43. The crystal structure of meisserite (R1= 0.018 for 3306 reflections withIobs> 3σI) is topologically unique among known structures of uranyl minerals and inorganic compounds. It contains uranyl pentagonal bipyramids linked by SO4groups to form chains. Na+cations bond to O atoms in the chains and to an SO3OH group and an H2>O group between the chains, thereby forming a heteropolyhedral framework.

*Corr esponding author Bluelizardite (IMA 2013-062), Na 7 (UO 2 )(SO 4 ) 4 Cl(H 2 O) 2 , is a new uranyl sulfate mineral from the Blue Lizard mine, San Juan County, Utah (USA). It was found in a sandstone matrix and is associated with chalcanthite, copiapite, ferrinatrite, gypsum, krohnkite, johannite, and several other new, unnamed Na- and Mg-containing uranyl sulfates. Bluelizardite is a supergene mineral formed by the post-mining weathering of uraninite. The mineral is monoclinic, C2/c, with a = 21.1507(6), b = 5.3469(12), c = 34.6711(9) A, β = 104.913(3)°, V = 3788.91(17) A 3 and Z = 8. Crystals are blades up to 0.4 mm long, flattened on {001}, elongated parallel to [010] and exhibiting the forms {100}, {001} and {111}. Bluel izardite is pale yellow and has a yellowish-white streak. It has good cleavage on {001} and uneven fracture. The Mohs hardness is estimated at 2. The calculated density based on the empirical formula is 3.116 g/cm 3 . Bluelizardite exhibits bright yellow-green fluorescence under both long- and short-wave UV radiation. The mineral is optically biaxial (–), with α = 1.515(1), β = 1.540(1) and γ = 1.545(1) (measured with white light). The measured 2V is 48(2)° and the calculated 2V is 47.6°. The mineral does not exhibit any dispersion or pleochroism. The optical orientation is X = b, Y ≈ a, Z ≈ c*. The empirical formula of bluelizardite is Na 6.94 (U 1.02 O 2 )(SO 4 ) 4.00 Cl 0.94 O 0.06 (H 2 O) 2 (based on 21 anions pfu). The Raman

Bluebellite, 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)9.80Cl1.09 based 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)(21), 2.213(9)(006), 2.103(29)(033,214), 1.899(47)(312,21), 1.566(48)(140,217) and 1.479(29)(045,14,324).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)(21), 2.110(27)(033,214), 1.889(34)(312,21,22), 1.570(39)(404,140,217), 1.481(34)(045,14,324) 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 Cu6MX14 layers, 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.

Lasalite, Na 2 Mg 2 [V 10 O 28 ] ·20H 2 O, is a new mineral species from the Vanadium Queen mine, La Sal District, Utah, U.S.A.; the mineral is named after the mining district in which it was discovered. Lasalite occurs in efflorescences on the sandstone walls of the mine workings and in fractures in the sandstone. The mineral forms by oxidation of the primary vanadium oxide bronze phase (corvusite) by vadose water and reaction with dolomite and calcite cement of the host sandstone. Lasalite is yellow to yellow-orange with a yellow streak, and transparent with an adamantine luster. The Mohs hardness is 1; crystals are very brittle and shatter with the slightest pressure. No cleavage was observed. The density, measured with a Berman balance using an 8.4 mg sample, is 2.38(2) g/cm 3 , and the calculated density is 2.362 g/cm 3 , using the empirical formula. Lasalite crystallizes as blocky crystals elongate parallel to [010] to massive crusts of rounded crystals, up to 1–2 mm in diameter. On euhedral crystals, the forms present are {100}, {010}, {001}, {111} and {111}. Twinning has not been observed. Lasalite dehydrates rapidly under the electron beam and is soluble in water. Therefore, the chemical analysis was performed by wet-chemistry methods, yielding (oxide, wt.%) Na 2 O 4.06, MgO 5.42, CaO 1.75, K 2 O 0.47, V 2 O 5 61.85, SO 3 2.55, H 2 O (difference) 23.88. The analyses yield the empirical formula (Na 1.84 Ca 0.44 K 0.14 ) ∑2.42 Mg 1.89 (V 9.55 S 0.45 ) ∑10.00 O 28.55 ·18.61H 2 O (formula basis: V + S = 10 apfu ); on the basis of the crystal structure, the ideal formula is Na 2 Mg 2 [V 10 O 28 ] ·20H 2 O. The 2 V x for this optically negative biaxial mineral was determined at three wavelengths, 550 nm: 32(1)°, 589 nm: 43(1)°, and 650 nm: 53(1)°; lasalite thus exhibits strong r > v dispersion. The pleochroic formula is X light greenish yellow, Y light yellow, Z light brown. The indices of refraction are: α 1.743(5), β 1.773(5), γ 1.780(5) (at 589 nm). Lasalite is monoclinic, C 2/ c , with a 23.9019(7), b 10.9993(3), c 17.0504(5) A, β 118.284(1)°. The structure was determined using direct methods and three-dimensional X-ray-diffraction data measured with a CCD detector and refined to R = 0.0289. The mineral is a member of the pascoite group of minerals, which have a structural unit containing the [V 10 O 28 ] 6− decavanadate polyanion. In lasalite, the fully hydrated interstitial group has a composition of {Na 2 Mg 2 (H 2 O) 20 } 6+ . The interstitial unit is formed of Mg(OH 2 ) 6 octahedra and seven-coordinated Na atoms that occur in a [Na 2 O 6 (OH2) 6 ] dimer. The Na-complex dimer of the interstitial unit links to the structural unit by hydrogen bonding and by sharing oxygen atoms with the decavanadate group, whereas the Mg(OH 2 ) 6 shares none of its oxygen with any other polyhedron, bonding to the structural unit only through hydrogen bonding.

A new mineral species of the mica group, fluorluanshiweiite, ideally KLiAl1.5□0.5(Si3.5Al0.5)O10F2, has been found in the Nanyangshan LCT (Li, Cs, Ta) pegmatite deposit in North Qinling Orogen (NQO), central China. Fluorluanshiweiite can be regarded as the F-dominant analogue at the A site of luanshiweiite or the K-dominant analogue at the I site of voloshinite. It appears mostly in cookeite as a flaky residue, replaced by Cs-rich mica, or in the form of scale aggregates. Most individual grains are <1 mm in size, with the largest being ca. 1 cm, and the periphery is replaced by cookeite. No twinning is observed. The mineral is silvery white as a hand specimen, and in a thin section, it appears grayish-white to colorless, transparent with white streaks, with vitreous luster and pearliness on cleavage faces. It is flexible with micaceous fracture; the Mohs hardness is approximately 3; the cleavage is perfect on {001}; and no parting is observed. The measured and calculated densities are 2.94(3) and 2.898 g/cm3, respectively. Optically, fluorluanshiweiite is biaxial (–), with α = 1.554(1), β = 1.581(1), γ = 1.583(1) (white light), 2V(meas.) = 25° to 35°, 2V(calc.) = 30.05°. The calculated compatibility index based on the empirical formula is −0.014 (superior). An electron microprobe analysis yields the empirical formula calculated based on 10 O atoms and 2 additional anions of (K0.85Rb0.12Cs0.02Na0.03)Σ1.02[Li1.05Al1.44(□0.47Fe0.01Mn0.02)Σ0.5] Σ2.99(Si3.55Al0.45) Σ4O10F2, which can be simplified to KLiAl1.5□0.5(Si3.5Al0.5)O10F2. Fluorluanshiweiite is monoclinic with the space group C2/m and unit cell parameters a = 5.2030(5), b = 8.9894(6), c = 10.1253(9) Å, β = 100.68(1)°, and V = 465.37(7) Å3. The strongest eight lines in the X-ray diffraction data are [d in Å(I)(hkl)]: 8.427(25) (001), 4.519(57) (020), 4.121(25) (021), 3.628(61) (112), 3.350(60) (022), 3.091(46) (112), 2.586(100) (130), and 1.506(45) (312).

Alfredopetrovite, Al 2 (Se 4+ O 3 ) 3 · 6H 2 O, is a new secondary selenite mineral from the El Dragon mine, Antonio Quijarro Province, Potosi Department, Bolivia. The mineral occurs in vugs in a matrix of Co-rich krut’aite–penroseite, dolomite and goethite. Associated minerals are: ahlfeldite, allophane, calcite, chalcomenite, favreauite, felsőbanyaite, malachite and molybdomenite. Crystals occur in drusy/scaly coatings and compact balls, the latter to 0.5 mm in diameter. Individual crystals are up to about 0.1 mm across. The Mohs hardness of alfredopetrovite is 2½; it has no cleavage, curved fracture and a vitreous lustre. The calculated density based on the empirical formula is 2.504 g cm −3 . Alfredopetrovite is uniaxial (+), with ω = 1.554(2) and e = 1.566(2) (white light), and exhibits no pleochroism. Electron microprobe analyses gave the empirical formula Al 1.94 Cu 0.07 Ni 0.03 Co 0.01 Se 2.95 O 15 H12.16, based on 15 O apfu . Alfredopetrovite is hexagonal, space group P 6 ¯ 2 c , with the unit-cell parameters: a = 8.818(3) A, c = 10.721(2) A, V = 722.0(5) A 3 and Z = 2. The eight strongest lines in the X-ray powder diffraction pattern are [ d obs /A ( I ) ( hkl )]: 7.63(55)(100), 6.22(55)(101), 5.37(26)(002), 4.398(40)(110,102), 3.404(100)(112), 2.783(50)(211), 2.606(22)(203), and 1.6609(26)(410,322,314,116). The crystal structure was refined to R 1 = 0.0268 for 240 observed reflections [ F o > 4σ F ]. The structure is comprised of fairly regular AlO 6 octahedra and Se 4+ O 3 triangular pyramids. Three Se 4+ O 3 pyramids link two adjacent AlO 6 octahedra forming a [Al(H 2 O) 3 | 2 (Se 4+ O 3 ) 3 cluster structural unit. These structural units are bonded to one another only via hydrogen bonds yielding a structure with relatively large channels along [001]. The configuration of the cluster is similar to that of the distinctive unit in the NASICON structure, commonly referred to as a lantern unit .

The new mineral yellowcatite (IMA2024-030), KNaFe3+2(Se4+O3)2(V5+2O7)·7H2O, was found underground in the School Section #32 mine, Grand County, Utah, USA, where it is a secondary, post-mining phase occurring on montroseite-corvusite-asphaltite-mica-bearing sandstone in association with barnesite, gypsum and mandarinoite. Crystals are thin hexagonal plates, up to ∼0.2 mm in diameter. Crystals are yellow and transparent, with vitreous to pearly lustre and pale-yellow streak. The mineral is brittle with curved fracture and two cleavages: perfect on {001} and good on {100}. The Mohs hardness is ∼2. The measured density is 2.79(2) g·cm–3. Optically, yellowcatite is uniaxial (–) with ω = 1.910(5) and ε = 1.740(5) (white light). The mineral is pleochroic with O yellow and E colourless; O > E. The empirical formula is (K0.65□0.35)Σ1.00(Na0.66Mg0.30)Σ0.96Fe3+2.02Se4+1.99V5+2.01O20H14.02. Yellowcatite is hexagonal, space group P $\bar 6$ m2, with cell parameters: a = 5.4966(7), c = 17.2109(16) Å, V = 450.31(13) Å3 and Z = 1. In the crystal structure of yellowcatite (R1 = 5.12% for 281 I > 2σI reflections), Fe3+O6 octahedra, Se4+O3 pyramids and V5+O4 tetrahedra link by corner-sharing to form sheets similar to those in the well-known merwinite structure, but with the apices of the Se4+O3 pyramids in the ‘pinwheels’ pointing in the same direction as the V5+O4 tetrahedra. The unshared vertices of the V5+O4 tetrahedra in adjacent sheets link to one another to form divanadate groups, thereby joining two sheets into a double-sheet slab structural unit. Between adjacent slabs is a layer of unlinked Na(H2O)6 coordinations that are presumed to represent octahedra exhibiting rotational disorder.

Camaronesite (IMA 2012-094), [Fe3+(H2O)2(PO3OH)]2(SO4)·1–2H2O, is a new mineral from near the village of Cuya in the Camarones Valley, Arica Province, Chile. The mineral is a low-temperature, secondary mineral occurring in a sulfate assemblage with anhydrite, botryogen, chalcanthite, copiapite, halotrichite, hexahydrite, hydroniumjarosite, pyrite, römerite, rozenite and szomolnokite. Lavender-coloured crystals up to several mm across form dense intergrowths. More rarely crystals occur as drusy aggregates of tablets up to 0.5 mm in diameter and 0.02 mm thick. Tablets are flattened on {001} and exhibit the forms {001}, {104}, {015} and {018}. The mineral is transparent with white streak and vitreous lustre. The Mohs hardness is 2½, the tenacity is brittle and the fracture is irregular, conchoidal and stepped. Camaronesite has one perfect cleavage on {001}. The measured and calculated densities are 2.43(1) and 2.383 g/cm3, respectively. The mineral is optically uniaxial (+) with ω = 1.612(1) and ε = 1.621(1) (white light). The pleochroism is O (pale lavender) > E (colourless). Electron-microprobe analyses provided Fe2O331.84, P2O529.22, SO315.74, H2O 23.94 (based on O analyses), total 100.74 wt.%. The empirical formula (based on 2 P a.p.f.u.) is: Fe1.94(PO3OH)2(S0.96O4)(H2O)4·1.46H2O. The mineral is slowly soluble in concentrated HCl and extremely slowly soluble in concentrated H2SO4. Camaronesite is trigonal, R32, with cell parameters:a = 9.0833(5), c = 42.944(3) Å, V = 3068.5(3) Å3 and Z = 9. The eight strongest lines in the X-ray powder diffraction pattern are [dobs Å (I)(hkl)]: 7.74(45)(101), 7.415(100)(012), 4.545(72)(110), 4.426(26)(018), 3.862(32)(021,202,116), 3.298(93)(027,119), 3.179(25)(208) and 2.818(25)(1·1·12,125). In the structure of camaronesite (R1 = 2.28% for 1138 Fo > 4σF), three types of Fe octahedra are linked by corner sharing with (PO3OH) tetrahedra to form polyhedral layers perpendicular to c with composition [Fe3+(H2O)2(PO3OH)]. Two such layers are joined through SO4 tetrahedra (in two half-occupied orientations) to form thick slabs of composition [Fe3+(H2O)2(PO3OH)]2(SO4). Between the slabs are partially occupied H2O groups. The only linkages between the slabs are hydrogen bonds. The most distinctive component in the structure consists of two Fe octahedra linked to one another by three PO4 tetrahedra yielding an [Fe2(PO4)3] unit. This unit is also the key component in the sodium super-ionic conductor (NASICON) structure and has been referred to as the lantern unit. The polyhedral layers in the structure of camaronesite are similar to those in the structure of taranakite. The Raman spectrum exhibits peaks consistent with sulfate, phosphate, water and OH groups.

Fulbrightite (IMA2019–032), Ca(VO)2(AsO4)2·4H2O, is a new mineral from the Packrat mine, near Gateway, Mesa County, Colorado, USA, and from the Rovnost mine, Jáchymov, Czech Republic. It is a low-temperature secondary phase. The mineral most typically occurs in shades of light green and forms rosettes of roughly square (pseudotetragonal) plates. The streak is colorless to pale green and the luster is vitreous to pearly. The Mohs hardness is about 2½. Crystals are brittle, but slightly flexible in thin plates. Cleavages are (001) perfect, (100) and (010) excellent, (110) and fair. Fracture is stepped, irregular, and curved. The measured density is 3.12(2) g/cm3. The mineral is optically biaxial (–), α = 1.675(3), β = 1.718(3), and γ = 1.718(3) (white light); 2V ≈ 5°; orientation: X ≈ c; pleochroism: X colorless, Y and Z pale green (X < Y = Z). Electron-microprobe analyses gave the empirical formulae Ca0.99(V4+1.00O)2[(As5+0.98V5+0.02)O4]2·4(H2.005O) (Packrat mine) and (Ca1.02Fe0.01Ba0.01)Σ1.04(V4+O)1.96[(As5+0.99P0.01)O4]2·4.04H2O (Rovnost mine). X-ray powder diffraction (coupled with the chemical analyses) showed fulbrightite to be the arsenate analog of sincosite. The mineral is triclinic, space group P1, with cell parameters a = 6.434(8), b = 6.480(8), c = 6.718(8) Å, α = 107.90(6), β = 94.06(4), γ = 90.06(3)°, V = 265.8(6) Å3, and Z = 1. The Raman and infrared spectra of fulbrightite and sincosite are consistent with them being arsenate and phosphate analogs, respectively.

Abstract. Karlseifertite (IMA 2024-007, International Mineralogical Association), Pb(Ga2Ge)(AsO4)2(OH)6, is a new member of the dussertite group, from Tsumeb, Namibia. It is a secondary oxidation-zone mineral found on fracture surfaces in germanite–chalcocite ore. Karlseifertite occurs in rosettes of thin, yellow, hexagonal plates up to about 0.2 mm in diameter and usually less than 0.01 mm thick. The mineral has a pale-yellow streak, subadamantine lustre, Mohs hardness of ∼ 4, brittle tenacity, irregular fracture, perfect cleavage on {001} and a calculated density of 4.993 g cm−3. Optically, karlseifertite crystals are uniaxial (+), with ω=1.890(5) and ε=1.894(calc) (white light). The empirical formula from electron probe microanalyses is Pb0.992+(Ga1.603+Ge0.684+Fe0.573+Al0.123+)Σ2.97[(As0.765+S0.156+W0.096+)Σ1.00O4]2(OH0.99)6. Karlseifertite is trigonal with space group R3‾m and unit-cell parameters a=7.2814(7), c=17.1077(12) Å, V=785.50(15) Å3 and Z=3. The mineral has an alunite-supergroup structure (R1=0.0591 for 248 reflections with I>2σI).

Abstract. The new mineral pilanesbergite, with the ideal formula Na2Ca2Fe2Ti2(Si2O7)2O2F2, was found in a nepheline syenite, locally known as green foyaite, from the Pilanesberg Complex located in the North West Province of South Africa. Pilanesbergite occurs in green foyaite in association, and partly intergrown, with aegirine. The two minerals share an assemblage of inclusions, comprising euhedral nepheline, titanite and minor sodalite. Pilanesbergite belongs to the wöhlerite group and is isomorphic with låvenite, normandite and madeiraite. It is related to these species through the homovalent chemical substitutions Mn2+↔Fe2+ and Zr4+↔Ti4+. The empirical formula calculated on the basis of 18 anions is Na2.00(Ca1.74Na0.26)Σ2.00(Fe1.00Mn0.52Ca0.49Zr0.05)Σ2.06(Ti1.69Zr0.14Mg0.09Nb0.08)Σ2.00(Si2O7)2.00O1.84F2.16 (Z=2). The new mineral is translucent with a brown orange colour and a brownish streak. The Mohs hardness is estimated between 5 and 6 by comparison with låvenite, and no cleavage is observed. Measured and calculated densities are Dmeas=3.47 g cm−3 and Dcalc=3.40 g cm−3. In the thin section the pleochroism is strong, between straw yellow and orange red, while in immersion the strong pleochroism is observed between light yellow (α) and yellowish orange (γ). The crystals are optically biaxial (+) with α=1.743(3), β=1.768(3), γ=1.795(5) and a 2 V angle close to 90∘. The crystal structure is monoclinic (P21/a), with the unit-cell parameters a=10.7811(2), b=9.7836(1), c=7.0348(1) Å, β=108.072(2)∘ and V=705.41(2) Å3, and has been refined to R1=2.06 %. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (h k l)] are 3.219 (60) (310), 2.851 (100) (12-2), 2.802 (51) (320), 2.743 (27) (22-2), 2.423 (19) (40-2) and 1.723 (19) (44-2). Pilanesbergite formed under relatively reducing conditions from an agpaitic nepheline syenite magma that had evolved by fractional crystallization mainly of aegirine. Further crystallization of arfvedsonite caused an increase in oxygen fugacity and a change towards higher Mn/Mn+Fe of the magma, causing a change of mineral composition from pilanesbergite towards normandite.

Fluorowardite (IMA2012-016), NaAl₃(PO₄)₂(OH)₂F₂·2H₂O, the F analog of wardite, is a new mineral from the Silver Coin mine, Valmy, Iron Point district, Humboldt County, Nevada, U.S.A., where it occurs as a low-temperature secondary mineral in complex phosphate assemblages rich in Al, Na, and F. Fluorowardite forms colorless to white or cream-colored, tetragonal-pyramidal crystals up to 0.1 mm in diameter. The streak is white. Crystals are transparent to translucent, with vitreous to pearly luster. The Mohs hardness is about 5, the tenacity is brittle, the fracture is irregular, and crystals exhibit one perfect cleavage on {001}. The calculated density is 2.760 g/cm³. Optically, fluorowardite is uniaxial positive, with ω = 1.576(2) and ɛ = 1.584(2) (white light) and is non-pleochroic. Electron microprobe analyses (average of 8) provided: Na₂O 6.27, CaO 1.74, MgO 0.42, Al₂O₃ 35.21, Fe₂O₂ 0.72, P₂O₅ 32.49, As₂O₅ 0.64, F 6.76, O=F −2.85, H₂O 13.35 (structure), total 94.74 wt%. The presence of H₂O and OH and the absence of CO₃ were confirmed by FTIR spectroscopy. The empirical formula (based on 14 anions) is: Na_(0.87)Ca_(0.13)Mg_(0.04))_(∑1.04)(Al_(2.96)Fe^(3+)_(0.04))_(∑3.00)(P_(1.96)As_(0.03))_(∑1.99)O_(8.12)(OH)_(2.35)F_(1.53)·2H_2O. Fluorowardite is tetragonal, P4_12_12, ɑ = 7.077(2), c = 19.227(3) Å, V = 962.8(5) Å^3, and Z = 4. The eight strongest lines in the X-ray powder diffraction pattern are [d_(obs) in Å(I)(hkl)]: 4.766(100)(004,103); 3.099(75)(211,203); 3.008(62)(115,212); 2.834(28)(204,213); 2.597(56)(205); 1.7628(32)(400,401); 1.6592(29)(multiple); and 1.5228(49)(423, 2·2·10). The structure of fluorowardite (R_1 = 3.15% for 435 F_o > 4σF) contains layers parallel to {001} consisting of Alϕ₆ (ϕ = F, O, OH or H₂O) octahedra, PO₄ tetrahedra, and NaO₆(H₂O)₂ polyhedra. The two independent Alϕ₆ octahedra link by corner-sharing to form a square array. Each PO4 tetrahedron shares corners with three adjacent octahedra in the same square array and a fourth corner with an octahedron in the next layer. The Na atoms reside in the “cavities” in the square array, forming bonds only to O atoms in the same layer. Of the two nearly identical OH sites in the wardite structure, only one is occupied by F in the fluorowardite structure. This is an interesting example of a structure in which OH and F are selectively incorporated into two different, but similar, sites as the result of rather subtle hydrogen bonding influences.