Karwowskiite, Ca9(Fe2+0.5□0.5)Mg(PO4)7—A New Merrillite Group Mineral from Paralava of the Hatrurim Complex, Daba-Siwaqa, Jordan DOI Open Access
Evgeny V. Galuskin, Irina O. Galuskina, Joachim Kusz

et al.

Minerals, Journal Year: 2024, Volume and Issue: 14(8), P. 825 - 825

Published: Aug. 14, 2024

Crystals of karwowskiite, Ca9Mg(Fe2+0.5□0.5)(PO4)7, a new mineral the merrillite group, were found on an amygdule wall in central part anorthite–tridymite–diopside paralava Hatrurim Complex, Daba-Siwaqa, Jordan. The was filled with sulfide melt, which after crystallization gave differentiated nodule, consisting troilite and pentlandite parts containing tetrataenite nickelphosphide inclusions. Karwowskiite crystals are colorless, although sometimes greenish tint is observed. has vitreous luster. microhardness VHN25 365 (12), corresponding to 4 Mohs hardness scale. Cleavage not observed, fracture conchoidal. calculated density 3.085 g/cm3. uniaxial (−): ω = 1.638 (3), ε 1.622 (3) (λ 589 nm), pleochroism composition karwowskiite described by empirical formula: Ca9.00(□0.54Fe2+0.23Mg0.12Na0.04 Sr0.03 Ni0.03K0.01) Σ1.00Mg1.00(PO4)7.02. distinct from known minerals subgroup general formula A9XM[TO3(Ø)]7, where A Ca, Na, Sr, Y; X □; M Mg, Fe2+, Fe3+, Mn; T P; Ø O, that site it occupied Fe2+0.5□0.5. trigonal, space group R-3c 10.3375 (2) Å, c 37.1443 (9) V 3437.60 (17) Å3. crystallizes at temperatures lower than 1100 °C thin layer secondary melt forming walls amygdules gaseous channels as result contact heated gases by-products combustion process.

Language: Английский

Iron-based eutectics, a valuable geological record DOI
Oleg S. Vereshchagin, Vladimir V. Shilovskikh, Л. В. Камаева

et al.

Lithos, Journal Year: 2025, Volume and Issue: unknown, P. 108057 - 108057

Published: March 1, 2025

Language: Английский

Citations

0
Telluric iron assemblages as a source of prebiotic phosphorus on the early Earth: Insights from Disko Island, Greenland DOI Creative Commons
Oleg S. Vereshchagin, Maya O. Khmelnitskaya, Л. В. Камаева

et al.

Geoscience Frontiers, Journal Year: 2024, Volume and Issue: 15(5), P. 101870 - 101870

Published: May 21, 2024

Phosphorus is one of the key elements, which determined emergence primordial life on our planet. The source prebiotic phosphorus was most likely to be easily soluble compounds containing in negative form oxidation (e.g., phosphides). present paper first thorough investigation phosphide-bearing mineral assemblages confined telluric (terrestrial) native iron from volcanic rocks Disko Island, Greenland. speciation given varies solid solution (up 0.3 wt% P), different phosphides – schreibersite Fe3P, nickelphosphide Ni3P, barringerite Fe2P, and phosphates, including fluorapatite, anhydrous Fe-Na phosphoran olivine pyroxene 1 P). diversity observed can explained by steep changes redox conditions during subsurface crystallization iron-phosphide-bearing lavas. Based available data early Earth, we hypothesize that reactive may have originated shallow crustal rocks.

Language: Английский

Citations

2
Formation Conditions of Unusual Extremely Reduced High-Temperature Mineral Assemblages in Rocks of Combustion Metamorphic Complexes DOI Creative Commons
I. S. Peretyazhko, Е. A. Savina

Crystals, Journal Year: 2024, Volume and Issue: 14(12), P. 1052 - 1052

Published: Dec. 3, 2024

New data, including Raman spectroscopy, characterize unusual mineral assemblages from rocks of the Naylga and Khamaryn–Khyral–Khiid combustion metamorphic complexes in Mongolia. Several samples melilite–nepheline paralava other thermally altered (metamorphosed) sedimentary contain troilite (FeS), metallic iron Fe0, kamacite α-(Fe,Ni) or Ni-bearing taenite γ-(Fe,Ni) Ni-rich barringerite allabogdanite Fe2P, schreibersite Fe3P, steadite Fe4P = eutectic α-Fe + wüstite FeO, cohenite Fe3C. The matrix includes a fragment composed magnesiowüstite–ferropericlase (FeO–MgO solid solution), as well spinel (Mg,Fe)Al2O4 forsterite. highest-temperature assemblage belongs to xenolithic remnant, possibly Fe-rich sinter, which is molten ash left after underground coal seams. crystallization temperatures observed phases were estimated using phase diagrams for respective systems: Fe–S sulfides Fe–P ± C phosphides. Iron monosulfides (high-temperature pyrrhotite) with inclusions Fe0 underwent solid-state conversion into at 140 °C. phosphides early growth zone anorthite–bytownite crystallized <1370 1165 °C (Fe2P), 1165–1048 (Fe3P), <1048 (Fe4P). Phase relations zoned spherules consisting +Fe0 (or taenite) +Fe3P (Fe3C, Fe4P) reveal potential presence homogeneous Fe–S–P–C melt T~1350 °C, separated two immiscible melts 1350–1250 range; namely, dense Fe–P–C core less rim. evolved accordance cooling paths diagrams. Cohenite between 988 959 minerals used reconstruct redox patterns respect CCO, IW, IM, MW buffer equilibria during melting marly limestone subsequent melts. origin studied CM was explained model implying thermal alteration low-permeable overburden domains reducing conditions wild subsurface fires, while heating transferred conductively adjacent parts ignited fluid (gas) regime zones controlled by CCO excess atomic carbon. Paralava exposed high-temperature extremely contained droplets Fe–S–P–C, Fe–S, Fe–P, melts, then reduced assemblages.

Language: Английский

Citations

1
Karwowskiite, Ca9(Fe2+0.5□0.5)Mg(PO4)7—A New Merrillite Group Mineral from Paralava of the Hatrurim Complex, Daba-Siwaqa, Jordan DOI Open Access
Evgeny V. Galuskin, Irina O. Galuskina, Joachim Kusz

et al.

Minerals, Journal Year: 2024, Volume and Issue: 14(8), P. 825 - 825

Published: Aug. 14, 2024

Crystals of karwowskiite, Ca9Mg(Fe2+0.5□0.5)(PO4)7, a new mineral the merrillite group, were found on an amygdule wall in central part anorthite–tridymite–diopside paralava Hatrurim Complex, Daba-Siwaqa, Jordan. The was filled with sulfide melt, which after crystallization gave differentiated nodule, consisting troilite and pentlandite parts containing tetrataenite nickelphosphide inclusions. Karwowskiite crystals are colorless, although sometimes greenish tint is observed. has vitreous luster. microhardness VHN25 365 (12), corresponding to 4 Mohs hardness scale. Cleavage not observed, fracture conchoidal. calculated density 3.085 g/cm3. uniaxial (−): ω = 1.638 (3), ε 1.622 (3) (λ 589 nm), pleochroism composition karwowskiite described by empirical formula: Ca9.00(□0.54Fe2+0.23Mg0.12Na0.04 Sr0.03 Ni0.03K0.01) Σ1.00Mg1.00(PO4)7.02. distinct from known minerals subgroup general formula A9XM[TO3(Ø)]7, where A Ca, Na, Sr, Y; X □; M Mg, Fe2+, Fe3+, Mn; T P; Ø O, that site it occupied Fe2+0.5□0.5. trigonal, space group R-3c 10.3375 (2) Å, c 37.1443 (9) V 3437.60 (17) Å3. crystallizes at temperatures lower than 1100 °C thin layer secondary melt forming walls amygdules gaseous channels as result contact heated gases by-products combustion process.

Language: Английский

Citations

1