Ganophyllite from Franklin, New Jersey, Pajsberg, Sweden, and the Benallt Mine, Wales, has been chemically reinvestigated. Twelve new analyses confirm the general structure of Kato (1980) and yield the tentative formula (K,Na,Ca)2Mn8(Si,Al)12(O,OH)32(OH)4·8H2O. There is little solid solution among octahedral cations, and the Si:Al ratio is nearly constant at 10:2. Ca and (Na + K) are apparently differentiated, but all examined ganophyllites are K-rich. Much of the water content is loosely bound and the upper limit of water content is not well defined. Ganophyllite is relatively invariant in chemical composition from locality to locality.

Steverustite, ideally Pb52+(OH)5[Cu+(S6+O3S2–)3](H2O)2, is a new supergene mineral from the Frongoch mine dump, Devils Bridge, Ceredigion, Wales. It generally forms fibrous fan-like bundles that occur in small cavities in quartz veins with other supergene species. Crystals are fibrous to acicular, elongated along [010], and are bounded by (h0l) faces too small to index reliably. It is transparent, colourless to white with a white streak, has a vitreous lustre, does not fluoresce under ultraviolet light and is brittle with a splintery fracture. The calculated density is 5.150 g/cm3, and the calculated mean refractive index is 1.94. The mineral is monoclinic, P21/n, a 12.5631(7), b 8.8963(5), c 18.0132(11) Å, β 96.459(1)º, V 2000.5(3) Å3, Z = 4, a:b:c = 1.41217:1:2.02480. The seven strongest lines in the X-ray powder diffraction pattern are as follows: d (Å), I, (h k l): 3.934, 10, (Ī14); 3.934, 8, (Ī11); 3.348, 7, (313); 6.211, 6, (200); 4.797, 6, (211); 3.026, 6, (314); 2.837, 5, (016). Chemical analysis by electron microprobe gave PbO 72.59, SO3 15.78, Cu2O 4.47, S2– 6.32, H2O 4.83, O=S2– –3.15, total 100.84 wt.% where the amount of H2O was determined by crystal-structure analysis. The resulting empirical formula is Pb4.992+Cu0.96+(S6+O3S2–)3.03(OH)4.88(H2O)1.67, based on O + OH + H2O + S2– = 18.67 a.p.f.u. (atoms per formula unit) with H2O = 1.67 a.p.f.u. (from crystal-structure solution and refinement).

The crystal structure of steverustite was solved by direct methods and refined to R1 = 2.7% for 3366 unique (Fo > 4σF) reflections. There are five distinct Pb2+ cations with coordination numbers from [8] to [11], all of which show stereoactive lone-pair behaviour and which form a strongly bonded cluster of composition [Pb5(OH)5]. There is one Cu+ cation triangularly coordinated by three S2– atoms that belong to three thiosulphate groups, forming a Cu+(S6+O3S2–)3 group. The [Pb5(OH)5] units and [Cu(S2O3)3] groups occur at the vertices of interpenetrating 36 nets to form layers of composition [Pb5(OH)5Cu(S2O3)3] parallel to (010) which are linked by weaker bonds. Examination of the stereochemistry of thiosulphate and thionate structures shows that the combination of <S–O> and S–S distances are distinct for these two types of structures.

The textural and paragenetic relationships of sulphide and sulphosalt minerals within Cu-Pb-Sb-Bi hydrothermal vein mineralization at the Apollo mine, Siegerland, Germany, are interpreted in terms of various reaction sequences. An earlier primary sulphide mineralization hosted within a siderite vein of the Siegerland type, with pyrite, chalcopyrite, sphalerite and galena as main component phases, has been overprinted by Sb-, Bi- and Cu-rich fluids. This superposition resulted in the formation of new quartz-stibnite veins, and various mineral reactions with the primary sulphides including the formation of the sulphosalt minerals semseyite, tetrahedrite, meneghinite, jaskolskiite, boulangerite, bournonite and zinkenite. Based on microprobe analyses of reaction pairs and determination of mineral proportions in some cases, a series of quantitative data for each mineral reaction may be generated. This, in turn, allows for the construction of isocon diagrams permitting the relative mobility and immobility of all chemical elements involved in each reaction to be discussed. Two stages of reactive replacement are identified, characterized by immobile behaviour of S and supply of Sb and Cu during the first stage and relative immobility of S and Sb with no further supply of metals during the second stage. Formation of sulphosalts inside the siderite vein during the first stage is interpreted as a decrease of disequilibrium between hydrothermal fluids and pre-existing vein minerals. Replacement processes of the second stage are interpreted as an equilibration of geochemical contrasts between different points within the siderite vein and also between the siderite and quartz-stibnite vein systems. The geochemical evolution of fluid composition during the entire mineralizing event may therefore be modelled, based on the transfer of chemical components reflected in the succession of mineral reactions. Such an approach has applications to comparable polyphase mineralization sequences, in which an understanding of fluid evolution patterns may greatly assist in the development of genetic models for mineral deposits. Solid-state diffusion and grain-boundary diffusion are considered to be the dominant mechanisms for short-range mass transport, whereas diffusion of ionic and complex species through the fluid is considered to be of major importance in long-range mass transport.

Vysokýite, 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.

The new mineral lussierite (IMA2018-101), Na10[(UO2)(SO4)4](SO4)2(H2O)3, was found in the Blue Lizard mine, San Juan County, Utah, USA, where it occurs as pale green–yellow prisms or blades in a secondary assemblage with belakovskiite, ferrinatrite, halite, ivsite, metavoltine and thénardite. The streak is white and the fluorescence is bright cyan under 365 nm ultraviolet light. Crystals are transparent with vitreous lustre. The tenacity is brittle, the Mohs hardness is 2½, the fracture is irregular and no cleavage was observed. The mineral is easily soluble in H2O and has a measured density of 2.87(2) g cm–3. Lussierite is optically biaxial (+), with α = 1.493(1), β = 1.505(1) and γ = 1.518(1) (white light); 2Vmeas. = 88(1)°; dispersion is r > v, moderate; pleochroism: X = colourless, Y and Z = green yellow (X < Y ≈ Z); optical orientation: X = b, Z ∧ a = 44° in obtuse β. Electron microprobe analyses (wavelength-dispersive spectroscopy mode) provided Na10(U0.99O2)(S1.00O4)6·3H2O (+0.06 H for charge balance). The five strongest X-ray powder diffraction lines are [dobs Å(I)(hkl)]: 6.69(95)($\bar{1}$11,130), 4.814(100)(150,002,060), 3.461(83)(171,$\bar{2}$02), 2.955(81)(113,330) and 2.882(74)($\bar{1}$91,311,191,0·10·0). Lussierite is monoclinic, Cc, a = 9.3134(4), b = 28.7501(11), c = 9.6346(7) Å, β = 93.442(7)°, V = 2575.1(2) Å3 and Z = 4. The structure (R1 = 0.0298 for 5202 I > 2σI) contains a [(UO2)(SO4)4]6– uranyl sulfate cluster in which one SO4 tetrahedron shares an edge (bidentate linkage) with the UO7 pentagonal bipyramid. The uranyl sulfate clusters occur in layers and are linked through a complex network of bonds involving Na+ cations, isolated SO4 tetrahedra and isolated H2O groups.

The first known occurrence of kornerupine in Australia is described. The mineral is a minor component of a phlogopite-rich garnet-corundum-spinel metasomatic zone, which cuts mafic and ultranlafic spinel-plagioclase-orthopyroxene-hornblende rocks. The kornerupine-bearing assemblage was formed during the second major metamorphic episode that affected the terrain, probably under low-grade granulite or upper amphibolite facies conditions. Kornerupine appears to have formed at significantly lower levels of P-T than those reached in the terrain during the peak of the second granulite metamorphism.

A new magnesium aluminium phosphate mineral with the ideal formula Mg5Al12(PO4)4(OH)22·nH2O (n ⋍ 32) has been named aldermanite. It occurs as minute talc-like flakes, partly as an alteration product of fluellite, thinly coating cracks and cavities in a brecciated metamorphosed rock phosphate at Moculta, South Australia. Strongest X-ray diffraction lines are 13.40 Å (100) 002, 7.98 Å (80) 011, 5.55 Å (60) 210; unit cell parameters a= 15.00±0.007, b=8.330±0.006, c= 26.60±0.01 Å, Z = 2.

Bavenite is an orthorhombic calcium beryllium aluminosilicate, a ≈ 23.2, b ≈ 5.0, c ≈ 19.4 Å, V ≈ 2250 Å3, Z = 4, that crystallizes in the space group Cmcm. The crystal structures of 24 bavenite samples from various localities worldwide were refined to R1 values from 2.4 to 7.5% based on ∼1330 unique reflections collected with Mo-Kα X-radiation on a Bruker P4 CCD single-crystal diffractometer. The composition of each crystal was determined by electron microprobe analysis. There is extensive solid-solution in bavenite according to O(2)OH– + T(4)Si4+ + T(3)Be2+ ⇌ O(2)O2– + T(4)Al3+ + T(3)Si4+, such that the general formula may be written Ca4BexSi9Al4–xO28–x(OH)x, where x ranges from 2.00 to ∼3.00 a.p.f.u. Small amounts of additional Be may be incorporated into bavenite via the substitution T(3)Be + O(2)OH– + Na + T(4)Si2 ⇌ T(3)Si + O(2)O2– + Ca + T(4)Al2. Local (short-range) bond-valence considerations indicate that Short-Range Order (SRO) should be extensive in the bavenite structure, and this is confirmed by Fourier Transform Infrared (FTIR) spectroscopy in the principal OH-stretching region and by 27Al Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) spectroscopy. Short-range bond-valence considerations indicate that the T(3)–T(4)–T(3)–T(4) rings of the framework can incorporate any short-range arrangement of cations consonant with their site populations [T(3) = Be,Si; T(4) = Si,Al], and 27Al MAS NMR spectroscopy confirms this, showing the presence of the local clusters T(3)Be–T(4)Al–T(3)Be, T(3)Si–T(4)Al–T(3)Be and T(3)Si–T(4)Al–T(3)Si. Incorporation of Be at the T(3) site is accompanied by local replacement of O2– by (OH)– at the O(2) site and hydrogen bonding to the adjacent O(3) anion; the latter promotes Be → Si substitution at the T(3) tetrahedron adjacent in the b direction. T(3)–T(4)–T(3)–T(4) rings link in the c direction through a T(3)–(1)–(3) linkage [T(1) = Si]. Local bond-valence considerations show that occupancy of both T(3) tetrahedra by Be violates the valence-sum rule, and that the linkage T(3)Be–T(1)Si–T(3)Si provides the constraint whereby Be does not exceed 3 a.p.f.u. in bavenite when incorporated via the substitution O(2)OH– + T(4)Si4+ + T(3)Be2+ ⇌ O(2)O2– + T(4)Al3+ + T(3)Si4+.

A new mineral species of the pyrochlore supergroup, oxynatromicrolite (IMA2013-063), (Na,Ca,U)2Ta2O6O, was found in the No. 309 rare-metal granitic pegmatite vein, Guanpo, Lushi county, Henan Province, China, which is characterized by tantalum at theB site and oxygen at the Y site and is Na dominant at the A site. The mineral occurs as strongly metamict, and mostly euhedral octahedral crystals up to 0.05–0.20 mm across. The measured density of an unheated sample is 6.580(4) g cm–3, and the calculatedone is 6.506 g cm–3. Optically, the mineral is isotropic, with an index of refraction 1.999(5) and a reflectance of 11.88% (470 nm). When heated to 1000°C for 4 hours in N2, the mineral recrystallizes in the cubic system, with space group Fd3mand with unit-cell parameters similar those of other pyrochlore supergroup species: a = 10.420(6) Å, V = 1131.4(2) Å3. Electron microprobe analyses revealed the following composition of the mineral (in wt.%): Na2O 5.41, CaO 4.56, UO214.60, La2O3 0.16, Ce2O3 0.11, Nd2O3 0.13, PbO 0.62, Ta2O5 61.52, Nb2O5 8.21, Sb2O5 0.23, TiO2 0.05, SiO2 0.56, SnO2 0.29, F1.04, H2O 1.50 (calculated to correspond to 0.47 H2O pfu), F≡O –0.44, sum = 98.53%, which corresponds to the empirical formula (Na0.99Ca0.46U0.31Pb0.02La0.01H2O0.21)∑2.00(Ta1.58Nb0.35Si0.05Sn0.01Sb0.01)∑2.00O6 (O0.43F0.31H2O0.26)∑1.00, represented by the simplified formula (Na,Ca,U)2(Ta,Nb)2O6(O,F).Oxynatromicrolite crystallized during the late-stage of formation for the No. 309 pegmatite dyke and is associated with quartz, albite, potassium feldspar, muscovite, kaolinite, tantalite-Mn, stibiotantalite, pollucite, spodumene, montebrasite, Hf-rich zircon, a red tourmaline, polylithionite,trilithionite, luanshiweiite-2M1 (IMA2011-102) and a hydrated derivative of oxynatromicrolite.

Manganoan berthierine, sometimes only a few layers thick, is preserved interlayered with manganoan chlorite (chamosite) in small recrystallized patches in cherty metapelagites matamorphosed in the prehnite–pumpellyite facies at Meyers Pass, Torlesse Terrane, South Canterbury, New Zealand. The Mn occupies 11–12% of the octahedral sites, making this the most Mn–rich berthierine reported so far. The ratio (Fe+Mn)(Fe+Mn+Mg), 0.67–0.70, is at the lower end of those of previously reported occurrences, making these amongst the most Mg-rich berthierines known. Manganoan berthierine and interlayered manganoan chlorite also make up ~11–13% of the cryptocrystalline groundmass in which the berthierine is believed to have crystallized under early diagenetic conditions near a deep-ocean–sediment interface. The occurrence of berthierine in the recrystallized patches lends support to the possibility of a stability field at the temperature of prehnite-pumpellyite facies recrystallization in association with chlorite of similar but not identical composition.

The Penouta deposit is associated with a small Hercynian apogranite stock that intrudes Precambrian-Cambrian gneisses of the Ollo de Sapo Formation. Tin ore occurs as disseminations of cassiterite in the apogranite and as greisenized zones and quartz veins which traverse both the alkaline leucogranite and the surrounding metamorphic country rocks.

A fluid-inclusion study, utilizing microthermometric, crushing tests and Raman spectroscopic techniques on quartz from an intragranitic vein and a greisen of the host rock, indicates that the evolution of fluids was similar in both samples and occurred in the three main stages: The first stage is characterized by complex CO2 (CO2-N2-CH4-H2S) and complex CO2 aqueous (H2O-NaCl-CO2-N2-CH4-H2S) fluids of low salinity (Tm ice > −6°C), homogenization temperatures between 250 and 410°C homogenization pressures below 900 bars, and thermobarometric trapping conditions with temperatures below 700°C and pressures below 3250 bars. These fluids were probably responsible for the greisenization of the apogranite and wall rocks, and the precipitation of cassiterite. The second stage is represented by low-salinity aqueous solutions (H2O-NaCl) with Tm ice ⩾ −4.5°C, trapped at homogenization temperatures between 110 and 300 °C and homogenization pressures below 100 bars. This stage can be correlated with kaolinization. The third stage is characterized by higher salinity aqueous fluids (Tm ice ⩾ −16.5°C) containing Na+ and other cations, trapped at homogenization temperatures between 100 and 130°C and homogenization pressures below 5 bars. These fluids can be associated with the epigenetic or supergene phases of the orebody.

Childrenite (Fe,Mn)AlPO4,(OH)2.2H2O, the iron-rich end-member of the childrenite-eosphorite diadochic series, was first discovered by Brooke (1823) on specimens from near Tavistock in Devon. Subsequently it has been recorded from a small number of other British localities, mostly in the Tavistock area, and also from near St. Austell in Cornwall, and from one locality in Cumbria. The Sir Arthur Russell collection, now in the British Museum (Nat. Hist.), has specimens from a few additional localities, all near Tavistock, and the Geological Museum, Institute of Geological Sciences, has a specimen from Wheal Jane, near Truro.

Gabbroic-textured shonkinitic rocks of unknown age cut deformed Archaean dunites and peridotites in the area immediately north of Salem. Magnesite formation post-dates their intrusion. The location of these rocks and the magnesite is thought to be controlled by the intersection of two major basement lineaments. A sequence of crystallization of the minerals and rocks from early undersaturated to late oversaturated rocks is established. Compositions of the coexisting mineral phases are reported here for the first time. Clinopyroxenes, which are relatively unevolved, commonly coexist with olivine (chrysolite) and sanidine. Bronzite, often intergrown with magnetite and green spinel, is occasionally present. In the most undersaturated rocks nepheline-sanidine fingerprint intergrowths occur, whilst perthitic sanidine, albitic plagioclase, and quartz are present in over-saturated rocks. Late in the crystallization sequence, in over-saturated rocks, PH2O appears to have increased allowing the formation of amphibole as well as clinopyroxene.

Brianyoungite, which is chemically and structurally related to hydrozincite, occurs as white rosettes (<100 μm) with gypsum on rubbly limestone within the oxidised zone at Brownley Hill Mine, Nenthead, Cumbria. The mineral contains (wt.%) 71.47 ZnO, 9.90 CO2, 6.62 SO3 and 10.70 H2O+. Based on 29 oxygen atoms, the empirical formula is Zn11.73[(CO3)3.00,(SO4)1.10]4.10(OH)15.88 or ideally Zn3(CO3,SO4)(OH)4. Brianyoungite is either orthorhombic or monoclinic with β very close to 90° Cell parameters determined by electron diffraction and refined from X-ray powder diffraction data are a = 15.724, b = 6.256 and c = 5.427 Å. Density is > 3.93, < 4.09 g/cm3 (meas.) and 4.11 g/cm3 (calc.); Z = 4. Thermogravimetric analysis, IR and XRD powder data (23 lines) are presented.