Continental alkaline magmatic provinces are notable for their exceptional compositional diversity, making them valuable recorders of mantle source heterogeneity, magma differentiation processes, and volatile behavior. Some of these provinces occur in intraplate settings where evidence for rifting or plume activity is absent, leaving the cause of mantle melting and magma ascent enigmatic. Here, olivine-hosted melt inclusions provide insight into the source-to-surface evolution of the Ramon volcanics, the most diverse series of the Early Cretaceous intraplate Levant magmatic province, whose origin is enigmatic. Most data are derived from the well-preserved nephelinite-basanite-alkaline basalt series of the Ga'ash Hill edifice, complemented by additional exposures in Makhtesh Ramon, Negev Desert, Israel. Trace-element systematics indicate that compositional diversity is mostly dominated by low-degree melting of a garnet-bearing mantle source near the garnet-spinel transition, with contributions from peridotite and pyroxenite lithologies. Melt inclusions are CO2-rich (<= 3.19 wt %), while H2O contents are moderate with reconstructed values of up to 0.95 wt %. Volatile saturation pressures recorded in melt inclusions span a wide range (1300-230 MPa), further constrained by clinopyroxene geobarometry to indicate magma storage at lower-crustal levels (similar to 25-35 km), near the reconstructed Moho. Fluid-behavior modelling suggests a two-stage volatile control on melt mobilization: CO2 dominating deep transport and H2O becoming increasingly important at shallow levels below similar to 250 MPa, where eruptibility increases. Minimal interaction between ascending melts and crustal rocks is indicated by oxygen isotope ratios of olivine phenocrysts. Compositional diversity stems from the melting of a fertile lithospheric mantle source previously affected by carbonate-rich metasomatism, deep storage, and rapid ascent. Small perturbations in tectonic or thermal conditions may be sufficient to generate alkaline mafic melts from readily fusible carbonate- and pyroxenite-bearing lithospheric mantle, thus providing a possible explanation for magmatism in stable continental interiors that lack structural evidence for extension.

Metamorphosed phosphorites are exposed at the base of the Mottled Zone pyro-metamorphic complex in the Hatrurim Basin, Israel. Formed by recrystallization of unusually P-rich protoliths under extraordinary conditions, they provide insight on the effect of metamorphism on globally important natural resource and the behaviour of apatite under extreme high T, low P conditions. By studying the textures and assemblages of meta-phosphorites, measuring the chemical composition of apatite and dating it by U-Pb geochronology, the extent, characteristics and timing of combustion metamorphism around the Dead Sea basin are constrained, and an insight on the trigger of such events is provided. Our field, petrographic and geochemical analysis indicates peak metamorphic temperatures of >= 800 degrees C (locally exceeding 1170 degrees C) in apatite marbles immediately beneath Mottled Zone calc-silicate marbles and >= 525 degrees C in fluorapatite phosphorites at lower stratigraphic levels. Apatite recrystallization at high temperatures involved SiO2 and CO2 incorporation into its lattice, and formation of an assemblage dominated by non-silicates. Sulfide formation was constrained by fO2 and the SO3 content of the protolith and spurrite formation was controlled by the P2O5/SiO2 ratio. Metamorphism involved partial decarbonation, inhibited by CO2 incorporation into the apatite lattice. Mobilization of V and U during low T alteration of apatite marble is evident, but P2O5 mostly remained immobile. Thermally driven recrystallization of apatite during high T metamorphism resulted in isotopic homogenization of Pb and U-Pb system closure, enabling U-Pb geochronology based on spot analyses of apatite clusters. U-Pb dating of apatite records combustion events in the Hatrurim Basin in the Early Miocene (18 - 14 Ma), Late Miocene (12 - 10 Ma) and Pliocene (4.3 - 3.9 Ma), in accordance with previous age determinations. The first and last events correlate well with major tectonic events along the Dead Sea Transform. Sequential U-Pb ages of apatite in a single outcrop and textural evidence for metamorphic overprint require either partial preservation or replenishment of flammable material between combustion events.

Iron is one of the most common elements on Earth and is present in the modern crust mainly in the form of (hydro)oxides and silicates, whereas terrestrial (telluric) native Fe is extremely rare. It is generally assumed that telluric Fe differs greatly in its chemical composition and mineralogy from the metal of iron meteorites, indicating different modes of formation. We uncover haxonite (NiFe22C6) and uakitite (VN) within telluric iron assemblages in terrestrial crustal rocks (volcanic rocks of the Norilsk ore region, Russia and metamorphic rocks of the Hatrurim Basin, Israel, respectively). Both minerals were previously discovered in iron meteorites and were thought to be absent in Earth's crustal rocks. Consequently, we analyzed available data on terrestrial rocks containing native iron and iron meteorites and compared their oxygen-free mineral assemblages. The resemblance in mineralogy suggests that at least some metal-rich asteroids may have formed in a manner similar to telluric iron. We suggest that heating at low pressures (T approximate to 1000 degrees C, P < 10 MPa) of the primary Fe-bearing silicates in the presence of organic matter led to the formation of an iron melt at low oxygen fugacity (up to 5 units below Fe-FeO buffer). Significant differences in the geochemistry of terrestrial and extraterrestrial iron are associated with different degrees of evolution of the primary minerals involved in their formation.

Mampsisite is a new mineral in the hydrocalumite group-a family of natural layered double hydroxides (LDH), the analogs of cementitious calcium aluminates, or AFm phases. The mineral is the first purely carbonate member of the hydrocalumite group. Mampsisite was discovered in peralkaline hydrothermal assemblages confined to pyrometamorphic rocks of the Hatrurim Basin in the Negev Desert, near the Israeli coast of the Dead Sea. The mineral occurs in the cavities of marble-like larnite-brownmillerite-jasmundite rock, where it associates with katoite, portlandite, and other natural Ca-Al LDH: kuzelite Ca4Al2(OH)12(SO4)& centerdot;6H2O, hydrocalumite Ca4Al2(OH)12(Cl,CO3,OH)2 & centerdot;4H2O, and mariakrite Ca4Al2(OH)12(Fe2S4)& centerdot;4H2O. The assemblage was formed from residual highly alkaline solutions produced by late hydrothermal alteration of larnite, Ca2SiO4, and jasmundite, Ca11(SiO4)4 O2S. Mampsisite forms colorless platy crystals up to 50 mu m across with a perfect cleavage on {001}. Calculated density is 2.180 g & centerdot;cm-3. Chemical composition (electron microprobe, wt%, water, and CO2 calculated from structural data): CaO 39.12, Al2O3 17.66, CO2 7.66, H2O 34.49, total 98.93, corresponding to the empirical formula Ca4.01Al1.99(CO3)1.00(OH)11.99 & centerdot;5.00H2O or ideally Ca4Al2 (OH)12(CO3)& centerdot;5H2O. The mineral is triclinic, space group P1, a = 5.7834(2), b = 9.9274(3), c = 15.0972 (4) & Aring;, alpha = 87.198(2), beta = 89.805(2), gamma = 89.967(2)degrees, V = 865.75(5) & Aring;3, and Z = 2. The crystal structure (R1 = 0.053) represents an ordered 1:1 interstratification of two kinds of fully ordered layered units: the positively charged, carbonate-free hydrocalumite layer [Ca4Al2(OH)12(H2O)4]2+ and the negatively charged AFm layer of previously unknown type [Ca4Al2(OH)12(H2O)2(CO3)2]2-. The counter-charged layers are separated by two H2O molecules per formula unit, which are lying in the interlayer. This arrangement is different from that of synthetic AFm monocarboaluminate, which is composed of the uniform neutral units [Ca4Al2(OH)12(H2O)3(CO3)]0. However, both layer arrangements yield the same bulk chemical formula, Ca4Al2(OH)12(CO3)& centerdot;5H2O. The strongest lines of X-ray powder diffraction pattern of mampsisite [d in & Aring;(I)(hkl)]: 7.58(100)(002), 3.774(37)(004), 2.845(11)(131), 2.724(14)(132), 2.514(20)(203), 2.451(19)(133), 2.330(14)(134). It should be emphasized that basal interlayer spacing of mampsisite is almost identical to that of synthetic AFm monocarboaluminate and to basal spacings of 2:1 layered double hydroxides-quintinite, Mg4Al2(OH)12(CO3)& centerdot;3H2O, and the members of the quintinite group. The latter implies that mampsisite may be relatively common but a hidden constituent of cementitious materials and natural Ca-bearing clays, being readily misidentified with another polymorph of AFm monocarboaluminate and quintinite during the routine powder XRD analyses.

Shagamite, KFe11O17 (IMA 2020-091) was discovered in the ferrite zone of gehlenite hornfels from the Hatrurim Complex exposed near Mt. Ye'elim, Hatrurim Basin, Israel. The mineral occurs in outer zones of gehlenite rock blocks that were heterogeneously altered by high-temperature (>1200 degrees C) ferritization. Ferritization was induced by K-bearing fluids or melts, generated as a by-product of late combustion processes. Shagamite crystallized from a thin melt that formed on the rock surface during cooling to approximately 800-900 degrees C. It is mainly associated with minerals of the magnetoplumbite group like barioferrite, Sr-analog of barioferrite, and gorerite but also with magnetite, maghemite, harmunite, devilliersite and K(Sr,Ca)Fe23O36 hexaferrite. Shagamite is a modular compound with a beta-alumina-type structure (P6(3)/mmc, a = 5.9327 (5), c = 23.782 (3) angstrom, gamma = 120 degrees, V = 724.91 (13) angstrom(3), Z = 2), and it is isostructural with diaoyudaoite, NaAl11O17, and kahlenbergite, KAl11O17. Its structure is also closely related, though non-isotypic, to those of the magnetoplumbite-group minerals. Shagamite is dark brown with a semi-metallic luster and forms platy crystals flattened on (001). Its mean empirical formula is: (K1.00Ca0.15Mn0.052+Na0.04Rb0.01)(Sigma 1.25)(Fe10.36Mn0.152+Al0.14Mg0.12Zn0.10Ni0.07Cu0.03Cr0.023+Ti0.014+)(Sigma 11.00)O-17. The Vickers microhardness VHN25 = 507 kg/mm(2) corresponds to a Mohs hardness of similar to 5. The calculated density, based on the empirical formula and unit-cell parameters, is 4.12 g.cm(-3). The main bands in the Raman spectrum of shagamite occur at 685 and 715 cm(-1) and are assigned to nu(1)(FeO4)(5-) tetrahedral vibrations.

Rotemite, Ca4Cr2(OH)(12)Cl-24H(2)O, is a newly discovered mineral and the first Cr-bearing member of the hydrocalumite group within the hydrotalcite supergroup. The new mineral is a trigonal chromium analog of both hydrocalumite and its synthetic counterpart, Friedel's salt, representing a large family of novel compounds of lamellar/layered double hydroxides (LDH). This work presents the first comprehensive study of a Ca, Cr-bearing compound within the LDH family. Rotemite was discovered in pyrometamorphic rocks of the Hatrurim Complex, Israel. It forms tiny hexagonal platelet-shaped crystals that appear pale bluish-violet (daylight) to pinkish-violet (artificial light), depending on the type of illumination. The streak is pale light-purple. Optically, rotemite is negatively uniaxial with omega = 1.565(2), epsilon = 1.544(2) (lambda = 589 nm). It has a hardness of 2.5-3 on the Mohs scale. The crystals exhibit perfect cleavage on {0001}. The electron microprobe analyses indicated the empirical formula of (Ca3.94Sr0.01)(& sum;3.95)(Cr1.473+Al0.52Fe0.053+)(& sum;2.04)(OH)(12)[Cl-1.68(OH)(0.32)(SO4)(0.01)](& sum;2.01)4H(2)O. The calculated density, based on the empirical formula and unit cell parameters obtained from single-crystal X-ray diffraction data, is 2.18 g/cm(3). Single-crystal X-ray diffraction measurements have revealed that rotemite represents a 6-layered polytype with trigonal symmetry (R(3) over bar c)) and unit cell parameters: a = 5.7944(2) & Aring;, c = 46.69(4) & Aring;, V = 1357.7(10) & Aring;(3). The final structural model converged to R-1 = 0.0866. The structure consists of hydrocalumite-type layers [Ca-4(Cr,Al)(2)(OH)(12)(H2O)(4)](2+) with intercalated Cl- ions. Raman spectra of rotemite are characterized by a prominent band at similar to 525 cm(-1), typical of LDH compounds. Polarized Raman spectroscopy revealed that signals from OH stretching vibrations at 3441-3442 cm(-1) and 3609-3612 cm(-1) strongly depend on the orientation of the crystal relative to the polarization of the incident laser beam. This indicates both an ordered arrangement of water molecules and a perpendicular arrangement of OH bonds within the hydrocalumite layers, respectively. The origin of rotemite and other Cr3+-bearing minerals is discussed, along with the possible role of the [Cr(OH)(6)](3-) anion in their formation.

Phosphide-bearing diopside-anorthite paralava found in the distribution area of the pyrometamorphic rocks of the Hatrurim Complex in Jordan (Daba-Siwaqa field) and Israel (Hatrurim Basin field) have yielded a large number of new phosphides and phosphates. In 2019, a small outcrop of phosphide-bearing breccia with cement composed of gehlenite-flamite paralava was discovered in the Hatrurim Basin. A new pyrophosphate, yamhamelachite, KCrP2O7 (P21/c, a = 7.3574(3), b = 9.9336(4), c = 8.1540(4) & Aring;, beta = 106.712(5)degrees, V = 570.77(5) & Aring;3 and Z = 4), occurs at the phosphide-enriched boundary between an altered sedimentary xenolith and the gehlenite-flamite paralava. Yamhamelachite forms green aggregates in which the size of grains does not exceed 25-30 mu m. The mineral is transparent with a glassy lustre. Yamhamelachite is brittle with conchoidal fracture. Mohs hardness = 4. The empirical formula of yamhamelachite calculated on the basis of average microprobe analyses is (K0.89Ca0.01 square 0.10)Sigma 1.00 Cr3+0.50V3+0.33Al0.15Fe3+0.04 Ti4+0.03)Sigma 1.05P1.98O7. The density calculated from the empirical formula and structural data is 3.035 gcm-3. Cr3+ in yamhamelachite is substituted by V3+, and in a few cases V is marginally more abundant than Cr, indicating the presence of a potentially new mineral with the formula KVP2O7. Yamhamelachite consists of layers of Cr3+-octahedra and pyrophosphate groups connected at their apices, and potassium located within channels parallel to [001]. A characteristic feature of phosphide aggregates associated with yamhamelachite is the presence of two generations of barringerite, the earlier of which has higher Cr and V content. In the general crystallisation sequence, yamhamelachite appears after phosphides (+pyrrhotite and daubr & eacute;elite) and then spinels of the chromite-magnetite series crystallise, along with ferromerrillite and ferroalluaudite. The source of chromium for yamhamelachite was mainly V-Cr-bearing pyrrhotite and V-bearing daubr & eacute;elite. The low Fe3+ content in yamhamelachite, probably related to its late-stage alteration, indicates that it crystallised from phosphate melt under reducing conditions at similar to 1000 degrees & Scy;.

Apatite, an abundant accessory mineral in igneous and metamorphic rocks, may accommodate appreciable amounts of trace elements including U, Pb and REE and is thus a useful U-Pb geochronometer and tracer of high-temperature metasomatism. Since apatite is susceptible to recrystallization, new growth and fluid-induced chemical changes, a good understating of the U-Pb system closure in apatite at variable geological conditions is required to correctly interpret apatite U-Pb ages. In this research, we delve into the behavior of apatite in marine phosphorites metamorphosed at sanidinite facies conditions to constrain U-Pb systematics in apatite under extreme high-T low-P conditions. We sampled non-metamorphosed, metamorphosed, and hydrothermally altered marine phosphorites from the Mottled Zone pyrometamorphic complex exposures in the Hatrurim Basin, Israel. Petrographic study of the samples was followed by in -situ measurement of major (EMPA) and trace element compositions and U-Pb dating (LA-ICP-MS) of apatite. Our results show that during the pyrometamorphic event apatite recrystallized and incorporated carbonate, silica, and sulphate into its crystal lattice. Thermally derived apatite recrystallization resulted in a submillimeter-scale Pb isotopic homogenization, inheritance of common lead of very low 207Pb/206Pb ratio from the U-rich, biogenic apatite precursor, and contemporaneous U-Pb system closure of apatite on a wider scale. The Miocene and Pliocene U-Pb ages of apatite coincide with previously known 40Ar/39Ar and K-Ar ages of the Mottled Zone pyrometamorphic event (Gur et al., 1995). Post-metamorphic interaction of high-T metamorphosed phosphorites with carbonate-, uranyl- and vanadate-rich fluids resulted in U and V enrichment of apatite, as well as redistribution of REE. The results of our research shed new light on the timing and extent of the Mottled Zone pyrometamorphic event, contribute to understating the behavior of biogenic apatite under extreme high-T, low-P conditions, and exemplify the utilization of apatite in meta-sedimentary rocks for dating thermal events including combustion metamorphism.

The absence of primary sulfides challenges the interpretation of metal ore genesis, particularly where ore is hosted within several separate stratigraphic horizons. In the Timna Valley, S Israel, copper ore bodies occur mostly in Cambrian and Cretaceous sandstones and rarely in the underlying late Neoproterozoic Timna igneous complex (TIC), as secondary Cu-sulfides in veins and nodules and more abundantly as Cu-hydroxides. The timing and setting of copper mineralization in the TIC and its relation to the sedimentary ore are unknown. Quartz phenocryst-hosted fluid inclusion assemblages (FIA) in quartz porphyry (QP) stock and dykes are associated with sulfide inclusions of pyrite, chalcocite, and chalcopyrite, indicating a magmatic-hydrothermal genetic relationship. Mineralization-associated fluid inclusion assemblages (FIAs) in QP are: (FIA.a)

In anorthite-diopside-tridymite paralava of the Hatrurim Complex, Daba-Siwaqa, Jordan, phosphides from two facies environments were found. Large xenomorphic phosphide aggregates, presented by minerals of the barringerite-transjordanite series, murashkoite and zuktamrurite, were noted at the intimate contact of the paralava with the host rocks. Moreover, the contact facies of the paralava, composed of large diopside crystals up to 1 cm in size and cemented by hydrosilicates, zeolites, and calcite, are enriched in phosphides. In the contact facies, it was possible to observe pseudomorphs of barringerite and murashkoite after fish bones and inclusions of minute needle-like barringerite crystals in diopside with morphological manifestations of the simultaneous crystallization of these minerals. In the central part of the weakly altered paralava with abundant amygdules, two nodules containing ore minerals were detected. In the first nodule, barringerite and schreibersite were found; the second contained nickelphosphide. In this paper we discuss the hypothesis that phosphides at the contact facies of the paralava formed as a result of reducing carbothermal reactions with the participation of thermally altered and graphitized fish-bone remains as a source of carbon and phosphorus and oxidized pyrite framboids as an iron source: Fe2O3+3C = 2Fe(lq)+3CO(g), 2Ca5(PO4)3F+14C= 3P2(g)+14CO(g)+10Cao+F2(g) and nFe(lq)+1/2 P2(g) = FenP, where n = 1/2, 1, 2, 3. The process of phosphide formation during hot paralava injection, the temperature of which exceeded 1400 degrees C, into previously altered host rocks with contamination of material containing bone remains, took place in a small volume in a kinetic mode, which led to the preservation of the primary form of bone remains when they were replaced by phosphides. The formation of phosphides in the central part of the paralava occurred with the participation of gases that transported phosphorus reduced as a result of carbothermal reactions. The phosphorous was absorbed by drops of metal or sulfide melt, which led to the formation of phosphides.

Rotemite, Ca4Cr2(OH)12Cl2·4H2O, is a newly discovered mineral and the first Cr-bearing member of the hydrocalumite group within the hydrotalcite supergroup. The new mineral is a trigonal chromium analog of both hydrocalumite and its synthetic counterpart, Friedel's salt, representing a large family of novel compounds of lamellar/layered double hydroxides (LDH). This work presents the first comprehensive study of a Ca, Cr-bearing compound within the LDH family. Rotemite was discovered in pyrometamorphic rocks of the Hatrurim Complex, Israel. It forms tiny hexagonal platelet-shaped crystals that appear pale bluish-violet (daylight) to pinkish-violet (artificial light), depending on the type of illumination. The streak is pale light-purple. Optically, rotemite is negatively uniaxial with ω = 1.565(2), ε = 1.544(2) (λ = 589 nm). It has a hardness of 2.5–3 on the Mohs scale. The crystals exhibit perfect cleavage on {0001}. The electron microprobe analyses indicated the empirical formula of (Ca3.94Sr0.01)∑3.95(Cr3+1.47Al0.52Fe3+0.05)∑2.04(OH)12[Cl1.68(OH)0.32(SO4)0.01]∑2.01·4H2O.The calculated density, based on the empirical formula and unit cell parameters obtained from single-crystal X-ray diffraction data, is 2.18 g/cm3. Single-crystal X-ray diffraction measurements have revealed that rotemite represents a 6-layered polytype with trigonal symmetry (R3¯c) and unit cell parameters: a = 5.7944(2) Å, c = 46.69(4) Å, V = 1357.7(10) Å3. The final structural model converged to R1 = 0.0866. The structure consists of hydrocalumite-type layers [Ca4(Cr,Al)2(OH)12(H2O)4]2+ with intercalated Cl− ions. Raman spectra of rotemite are characterized by a prominent band at ∼525 cm−1, typical of LDH compounds. Polarized Raman spectroscopy revealed that signals from OH stretching vibrations at 3441–3442 cm−1 and 3609–3612 cm−1 strongly depend on the orientation of the crystal relative to the polarization of the incident laser beam. This indicates both an ordered arrangement of water molecules and a perpendicular arrangement of OH bonds within the hydrocalumite layers, respectively. The origin of rotemite and other Cr3+-bearing minerals is discussed, along with the possible role of the [Cr(OH)6]3− anion in their formation.

Ferro & aring;kermanite, Ca2FeSi2O7 - a new member of the melilite group, has been found in coarse-grained kirschsteinite-bearing paralava in the Hatrurim Basin outcrop between the Zohar and Halamish Wadies of the Hatrurim Complex in Israel. Ferro & aring;kermanite rarely forms single subhedral light-yellow crystals up to 30-50 mu m in size with a prismatic habit. The most common are irregular grains, aggregates and intergrowths with gehlenite or ferro & aring;kermanite crystals with perovskite inclusions. The mineral is transparent, exhibits vitreous lustre and has a distinct cleavage on (001). It is non-fluorescent, brittle and has a conchoidal fracture, a Mohs hardness of similar to 4.5-5 and a calculated density of 3.20 g/cm3. Ferro & aring;kermanite is uniaxial (-), omega = 1.652(3) and epsilon = 1.643(3) (lambda = 589 nm), and exhibits a visible pleochroism from light-yellow (omega) to intense yellow (epsilon). The empirical formula of ferro & aring;kermanite calculated on the basis of 7 O is (Ca1.77Na0.18Sr0.02Ba0.02K0.02)Sigma 2.01(Fe2+0.68Al0.28Mg0.04)Sigma 1.00(Si1.93Al0.07)Sigma 2.00O7. The chemical data obtained confirm the presence of ferro & aring;kermanite-gehlenite solid solution (Fe2+ + Si4+ <-> 2Al3+) in the studied rock, which was verified by Raman spectroscopy investigation. The crystal structure of the new mineral was refined to R = 0.0617 in the space group P $\overline4$21m with the following unit-cell parameters a = 7.7813(7) & Aring;, c = 5.0114(5) & Aring;, V = 303.43(6) & Aring;3, Z = 2. Ferro & aring;kermanite has a melilite-type structure with layers consisting of (Si2O7)6- disilicate units and (Fe2+O4)6- tetrahedra intercalated by layers formed of eightfold-coordinated Ca atoms. Moreover, the T1 site in the holotype specimen shows a mixed occupancy refined to 0.63(3) Fe2+ and 0.37(3) Al. The presence of rock-forming minerals such as gehlenite or rankinite suggests that the paralava analysed formed under high-temperature conditions, confirming that the new mineral ferro & aring;kermanite is indeed a high-temperature phase. Furthermore, the presence of Fe2+-bearing phases, such as kirschsteinite, ferro & aring;kermanite, chromite, ulv & ouml;spinel and bennesherite indicates the reduced conditions.

Hanswilkeite, KFe3+S2, is a new potassium-rich natural sulfide discovered in the pyrometamorphic suite of the Hatrurim Formation, southern Negev Desert, Dead Sea basin, Israel. The mineral occurs in sulfide-calcite assemblages confined to black-colored calcite-spurrite marbles. It forms single-crystal grains up to 1 mm in size, isometric to lath-like, and often intergrown with a less-common rasvumite, KFe2S3. Associated minerals include srebrodolskite, tilleyite, fluormayenite, cuspidine, fluorapatite, old-hamite, pyrite, and andradite.Macroscopically, hanswilkeite has a deep-purple color, dull metallic luster, and brown-black streak. The Mohs hardness is 2. Moderate cleavage was observed along the c-axis. The calculated density is 2.654 gcm-(3). The Raman spectrum contains the following bands: 379, 357, 289, 236, 167, 131, and 124 cm(-1). In reflected light, the mineral has very strong pleochroism from yellow-pink to dark-gray. Anisotropy is very strong, Delta R-589 = 69%. Reflectance values for COM required wavelengths measured in air, R-max/R-min (lambda, nm) (%): 16.0/9.2 (470); 19.6/9.3 (546); 18.5/9.0 (589); 32.0/9.3 (650). Chemical composition (electron microprobe, average of 6 points, wt%): K 23.78, Ca 0.44, Fe 34.75, Mn 0.60, Zn 0.47, S 39.46, Total 99.5, which corresponds to empirical formula (K0.98Ca0.02)(1.00) (Fe1.00Mn0.02Zn0.01)(1.03)S-1.98 (Sigma = 4 apfu) or ideally KFe3+S2. Single-crystal X-ray diffraction shows that the mineral is monoclinic, space group C2/c (#15), with unit-cell parameters a = 7.0914(5), b = 11.3154(5), c = 5.3992(3) & Aring;, beta = 113.244(7)degrees, V = 398.08(4) & Aring;(3), and Z = 4. Strongest lines of X-ray powder diffraction pattern [d in & Aring;(I)(hkl)]: 5.68(100)(020,110); 3.270(31)(130); 3.227(29)(111); 2.921(45)(221); 2.510(12)(131); 2.198(12)(132); 1.880(10)(330). The crystal structure has been solved and refined to R-1 = 0.038 for 454 unique observed reflections [I >= 2 sigma(I)]. The structure consists of infinite chains of edge-sharing tetrahedra [FeS4](-) centered with Fe3+; the sulfide chains are linked by K+ ions. Hanswilkeite is the third discovered dithioferrate mineral: a sulfosalt that contains [FeS2](-) anion with iron in Fe3+ state. Other known natural dithioferrates are erdite, NaFeS22H(2)O, and raguinite, TlFeS2. Hanswilkeite has a synthetic counterpart and a group of related synthetic sulfides and selenides, which were well studied due to specific electrical and magnetic properties owed to their quasi-one-dimensional structures. The mineral can be considered as an indicator of an extreme potassium-rich environment superimposed onto anhydrous and oxidizing formation conditions. The association with oldhamite is herein discussed in view of super-reduced conditions previously supposed for oldhamite geosynthesis.

Mariakrite is a new mineral in the hydrotalcite supergroup, and a member of a novel family of layered double hydroxides, or LDH. It is the first reported LDH with dithioferrate, [Fe3+S2]- as an interlayer anion, the first cementitious layered Ca-aluminate (AFm phase) intercalated with sulfide, and the first sulfide-intercalated LDH with a completely solved crystal structure. Mariakrite was discovered in late hydrothermal assemblages confined to pyrometamorphic lithologies of the Hatrurim Formation, in the Negev Desert on the Israeli side of the Dead Sea. The mineral forms saber-like crystals up to 2 mm long, 0.1 mm wide, and 0.5 to 2 mu m thick, residing in millimeter-sized cavities within larnite-jasmundite-brown-millerite rock. Associated minerals are katoite, portlandite, kuzelite, and hydrocalumite. Mariakrite has a purple-brown color with semimetallic luster; in transmitted light, it is transparent green-gray. The crystals are flexible and elastic. Mohs hardness is 3-3.5. Calculated density is 2.005 g cm(-3). In reflected light, the mineral exhibits extreme pleochroism, from gray to red-purple. Anisotropy is very strong. Reflectance values for four wavelengths recommended by the IMA Commission on ore mineralogy [in air, R-1/R-2, % (lambda, nm)] are: 5.0/5.2 (470), 6.3/2.3 (546), 6.7/1.8 (589), 6.6/17.6 (659). Mariakrite is triclinic (pseudo-monoclinic and pseudo-trigonal), space group P (1) over bar, a = 5.7107(2), b = 9.9952(4), c = 10.9095(4) angstrom, alpha = 98.678(3), beta = 90.100(3), gamma = 90.019(3) degrees, V = 615.58(4) angstrom(3), Z = 1. The 7 strongest lines of X-ray powder diffraction pattern are [d in angstrom (I)(hkl)]: 10.83 (100)(001), 9.90 (39)(010), 5.42 (75)(002), 3.96 (22)(0 (2) over bar2),3.523 (19)((1) over bar 12), 2.856 (37)(130), 2.400 (23)(132). The crystal structure, solved and refined to R-1 = 0.045 for 2379 independent observed reflections, consists of hydrocalumite-type LDH layers [Ca2Al(OH)(6)(H2O)(2)]+ intercalated with the iron disulfide chains. The latter are composed of edge-sharing tetrahedra [FeS4] forming dithioferrate (III) anion, [Fe3+S2](-). The hydrocalumite-like layers and sulfide chains are linked via the system of O-H center dot center dot center dot S hydrogen bonds. Chemical composition (electron microprobe, wt%, H2O based on the structural data) is: CaO 27.75, K2O 1.85, Al(2)O3 13.93, Fe 14.23, S 16.94, H2O 23.88, Total 98.58. The empirical formula calculated on the basis of Sigma(Ca,K,Al,Fe,S) = 12 apfu is (Ca3.73K0.30)(Sigma 4.03)Al-2.06(OH)(12.18)Fe1.92S3.99 center dot 3.91H(2)O, corresponding to the ideal formula [Ca4Al2(OH)(12)(H2O)(4)][Fe2S4]. Mariakrite is the first example of dithioferrate in which disulfide chains have no contacts with cations or anions, being suspended between hydroxide layers via the system of hydrogen bonds. Therefore, the mineral might represent the near-ideal model for the study of physical and chemical properties of isolated quasi-one-dimensional dithioferrate chains.

Rubinite, a garnet with the ideal formula Ca3Ti23+Si3O12, is an indicator of super-reduced conditions and has been found recently in refractory inclusions in a few CV3 chondrites. We discovered rubinite in phosphide-bearing breccia from the pyrometamorphic Hatrurim Complex, Negev Desert, Israel. Aggregates of phosphide and native iron are concentrated at the boundary of thermally altered sedimentary xenoliths encased in flamite-gehlenite paralava. Rubinite, with the average empirical formula (Ca2.97Mg0.02Fe0.012+)(Sigma 3.00)(Ti1.103+Al0.44Ti0.374+Mg0.08Cr0.01)(Sigma 2)(Si2.71Al0.29)(Sigma 3.00)O-12, was found in a small xenolith composed of hydrogrossular, tacharanite and calcite, and containing relics of high-temperature minerals such as pseudowollastonite, cuspidine, gehlenite, baghdadite, barringerite, murashkoite, osbornite, paqueite and oldhamite. For the first time, the structure of rubinite, with the composition (Ca2.99Mg0.01)(Sigma 3)(Ti0.783+Al0.62Ti0.434+Mg0.17)(Sigma 2)(Si2.74Al0.26)(Sigma 3)O-12, has been refined. Its unit-cell parameter a = 12.0193(4) & Aring;, is significantly smaller than that of the synthetic analogue of Ca3Ti2Si3O12, 12.1875 & Aring;. In the rubinite Raman spectrum weak bands corresponding to the vibrations of Ti4+-O in the (TiO6)(8-) octahedra: 610 cm(-1) nu(1)(TiO6)(8-) and 438 cm(-1) nu(4)(TiO6)(8-) are present in addition to the bands related to Si-O and Al-O vibrations in the TO4 tetrahedra. Rubinite forms a thin reactive rim (<10 mu m) on pseudowollastonite grains. It probably formed during a sharp increase in rock porosity in the course of natural clinkerisation of sedimentary xenoliths caused by the thermal impact of the paralava. The high porosity increased the effect of reductive gases on the rocks, which were by-products of pyrometamorphism. The brief appearance of super-reduced conditions defined the formation of the Ti3+-bearing minerals osbornite and rubinite. Paqueite, Ca3Ti4+(Ti4+Al2)Si2O14, which crystallised in a thin melting zone of xenolith at the boundary with the paralava, does not contain Ti3+.

Zoharite (IMA 2017-049), (Ba,K)6 (Fe,Cu,Ni)25S27, and gmalimite (IMA 2019-007), ideally K6□Fe2+24S27, are two new sulfides of the djerfisherite group. They were discovered in an unusual gehlenite–wollastonite paralava with pyrrhotite nodules located in the Hatrurim pyrometamorphic complex, Negev Desert, Israel. Zoharite and gmalimite build grained aggregates confined to the peripheric parts of pyrrhotite nodules, where they associate with pentlandite, chalcopyrite, chalcocite, digenite, covellite, millerite, heazlewoodite, pyrite and rudashevskyite. The occurrence and associated minerals indicate that zoharite and gmalimite were formed at temperatures below 800 °C, when sulfides formed on external zones of the nodules have been reacting with residual silicate melt (paralava) locally enriched in Ba and K. Macroscopically, both minerals are bronze in color and have a dark-gray streak and metallic luster. They are brittle and have a conchoidal fracture. In reflected light, both minerals are optically isotropic and exhibit gray color with an olive tinge. The reflectance values for zoharite and gmalimite, respectively, at the standard COM wavelengths are: 22.2% and 21.5% at 470 nm, 25.1% and 24.6% at 546 nm, 26.3% and 25.9% at 589 nm, as well as 27.7% and 26.3% at 650 nm. The average hardness for zoharite and for gmalimite is approximately 3.5 of the Mohs hardness. Both minerals are isostructural with owensite, (Ba,Pb)6(Cu,Fe,Ni)25S27. They crystallize in cubic space group Pm3¯m with the unit-cell parameters a = 10.3137(1) Å for zoharite and a = 10.3486(1) Å for gmalimite. The calculated densities are 4.49 g·cm−3 for the zoharite and 3.79 g·cm−3 for the gmalimite. The primary structural units of these minerals are M8S14 clusters, composed of MS4 tetrahedra surrounding a central MS6 octahedron. The M site is occupied by transition metals such as Fe, Cu, and Ni. These clusters are further connected via the edges of the MS4 tetrahedra, forming a close-packed cubic framework. The channels within this framework are filled by anion-centered polyhedra: SBa9 in zoharite and SK9 in gmalimite, respectively. In the M8S14 clusters, the M atoms are positioned so closely that their d orbitals can overlap, allowing the formation of metal–metal bonds. As a result, the transition metals in these clusters often adopt electron configurations that reflect additional electron density from their local bonding environment, similar to what is observed in pentlandite. Due to the presence of shared electrons in these metal–metal bonds, assigning fixed oxidation states—such as Fe2+/Fe3+ or Cu+/Cu2+—becomes challenging. Moreover, modeling the distribution of mixed-valence cations (Fe2+/3+, Cu+/2+, and Ni2+) across the two distinct M sites—one located in the MS6 octahedron and the other in the MS4 tetrahedra—often results in ambiguous outcomes. Consequently, it is difficult to define an idealized end-member formula for these minerals.

Metal iron-based eutectics are common in iron and stony-iron meteorites, where their presence traces space melting of parent celestial bodies or accompanies atmospheric ablation processes. It is less known that the same structures and compositions occur in situ within telluric iron in terrestrial crustal rocks. We have studied iron-based eutectics confined to native iron assemblages in volcanic rocks of Disko Island, Greenland, and combustion metamorphic lithologies of the Hatrurim Complex, Israel. In addition, Fe-P alloys were synthesized, enabling to reconstruct the composition and cooling rates of the initial melt. Despite the different geological settings of the two occurrences, the highly reducing (several units below iron - w & uuml;stite buffer) and high-temperature (similar to 1200 degrees C) environment results in the appearance of the same P-, C-bearing iron melts, with subsequent rapid crystallization (crystallization speed up to 5 degrees C/min) into eutectic structures (iron - cohenite (Fe3C), iron - schreibersite (Fe3P), cohenite - schreibersite and iron - barringerite (Fe2P)). The discovered eutectic structures clearly indicate the possibility of forming iron melt under conditions of low pressure and moderately high temperatures (typical for basalts), which may also be applicable to a number of celestial bodies.

Silicocarnotite, Ca5[(PO4)(SiO4)](PO4), was first described from slag over 140 years ago. In 2013, it was officially recognised as a mineral after being discovered in the larnite–gehlenite hornfels of the pyrometamorphic Hatrurim Complex. This paper describes the composition and structure of V-bearing silicocarnotite, crystals of which were found in a thin paralava vein cutting through the gehlenite hornfels. A network of thin paralava veins a few centimetres thick is widespread in the gehlenite hornfels of the Hatrurim Basin, Negev Desert, Israel. These veins, typically coarse crystalline rock and traditionally referred to as paralava, have a symmetrical structure and do not contain glass. Silicocarnotite in the paralava, whose primary rock-forming minerals are gehlenite, flamite, Ti-bearing andradite, rankinite and pseudowollastonite, was a relatively late-stage high-temperature mineral, crystallising at temperatures above 1100 °C. It formed from the reaction of a Si-rich residual melt with pre-existing fluorapatite. A single-crystal structural study of silicocarnotite (Pnma, a = 6.72970(12) Å, b = 15.5109(3) Å, c = 10.1147(2) Å) suggests that the phenomenon of Ca1 position splitting observed in this mineral is most likely related to the partial ordering of Si and P in the T2O4 tetrahedrons. Raman studies of silicocarnotite with varying vanadium content have shown that phases with V2O5 content of 3–5 wt.% exhibit additional bands at approximately 864 cm−1, corresponding to vibrations of ν1(VO4)3−.

Ferrodimolybdenite with ideal formula FeMo23+S4 (C2/c, a = 11.8249(8) angstrom, b = 6.5534(3) angstrom, c = 13.0052(10) angstrom, beta = 114.474(9)degrees, V = 917.27(12) angstrom(3) and Z = 8) was discovered in a differentiated sulfide nodule composed of troilite and pentlandite parts. The nodule was detected in the central zone of a diopside-anorthite-tridymite oval paralava body, similar to````````````````d30 metres in diameter, within the pyrometamorphic Hatrurim Complex in Daba-Siwaqa, Jordan. Ferrodimolybdenite is the first trivalent molybdenum compound discovered in nature. Its synthetic analogue crystallizes in the C1c1 space group. Ferrodimolybdenite with the empirical formula (Fe0.992+Cu0.072+Ni0.042+)(Sigma 1.10) Mo-1.94(3+)(S3.982-P0.023-)(Sigma 4.00) was identified in the troilite part of the differentiated sulfide nodule. The nodule contains inclusions of tetrataenite, nickelphosphide, molybdenite, galena and rudashevskyite. Ferrodimolybdenite forms platy crystals with dimensions ranging from 3x100 mu m to 20x40 mu m. The mineral exhibits a grey colour and a dark grey streak. It is opaque with a metallic lustre, and its Mohs hardness is approximately 3. The cleavage observed in the mineral is perfect on {001}, good on {100} and poor on {010}. Its tenacity is sectile, and its fracture is smooth. The calculated density of 5.445 g center dot cm(-3) was derived from the empirical formula and unit cell volume refined from single crystal XRD data. In reflected light, ferrodimolybdenite appears grey to light grey with a blueish tinge. It is anisotropic, with a reflectance in the range of 34-40%. The crystallization of ferrodimolybdenite occurred in reduced conditions in monosulfide Fe(+Ni) melt at a temperature of 1000-1100 degrees C and at low pressure.

Gorerite, ideally CaAlFe11O19 is a new mineral and M-type hexaferrite of the magnetoplumbite group. It was found in ferrite-rich segregations of esseneite-gehlenite-wollastonite-anorthite melted rock of the 'olive' subunit of pyrometamorphic rocks located near Hatrurim Junction in the Negev Desert, Israel. Within these ferrite-rich segregations up to 100 mu m in size, platy crystals of gorerite up to 50 mu m in size intergrow with hibonite, hematite, maghemite, magnesioferrite, dorrite, barioferrite and andradite, forming aggregates. Additionally, small crystals of gorerite occur within magnesioferrite. Importantly, gorerite did not crystallise directly from the melt. Instead, it emerged through a reaction involving earlier crystallised hibonite and an iron-enriched melt, resulting in the partial or complete replacement of hibonite by gorerite. Gorerite appears grey in the reflected light (R = 18-23%), displaying distinct bireflectance: dark-grey perpendicular to Z and light-grey parallel to Z. Its Raman spectrum exhibits only one strong band at 700 cm(-1), which shifts to higher frequencies with increasing Al content. Gorerite crystallises in the P6(3)/mmc space group, with lattice parameters a = 5.8532(4) & Aring;, c = 22.7730(2) & Aring; and V = 675.67(7) & Aring;(3) with Z = 2. It exhibits a structure characterised by an intercalation of triple spinel-like S blocks and rock-salt type R blocks along the hexagonal c-axis.