SEARCH · Search NASA
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
(Fe3(SO7)2)2O2 crystallizes in the trigonal R3m space group. The structure is two-dimensional and consists of three water molecules and three Fe3(SO7)2 sheets oriented in the (0, 0, 1) direction. In each Fe3(SO7)2 sheet, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with four equivalent FeO6 octahedra and corners with two SO4 tetrahedra. The corner-sharing octahedra tilt angles range from 39–43°. There are a spread of Fe–O bond distances ranging from 1.90–2.06 Å. There are two inequivalent S sites. In the first S site, S is bonded to four O atoms to form SO4 tetrahedra that share corners with three equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There is one shorter (1.46 Å) and three longer (1.50 Å) S–O bond length. In the second S site, S is bonded to four O atoms to form SO4 tetrahedra that share corners with three equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There is one shorter (1.45 Å) and three longer (1.50 Å) S–O bond length. There are six inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one S atom. In the second O site, O is bonded in a single-bond geometry to one S atom. In the third O site, O is bonded in a bent 120 degrees geometry to one Fe and one S atom. In the fourth O site, O is bonded in a bent 120 degrees geometry to one Fe and one S atom. In the fifth O site, O is bonded in a bent 150 degrees geometry to two equivalent Fe atoms. In the sixth O site, O is bonded in a bent 150 degrees geometry to two equivalent Fe atoms.
(Fe3(P4O17)2)2(O2)3 crystallizes in the monoclinic C2/c space group. The structure is two-dimensional and consists of twelve water molecules and two Fe3(P4O17)2 sheets oriented in the (0, 0, 1) direction. In each Fe3(P4O17)2 sheet, there are two inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with four PO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.91–1.99 Å. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with four PO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.87–2.00 Å. There are four inequivalent P sites. In the first P site, P is bonded in a trigonal planar geometry to four O atoms. There are a spread of P–O bond distances ranging from 1.49–2.45 Å. In the second P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with two FeO6 octahedra. The corner-sharing octahedra tilt angles range from 26–42°. There is three shorter (1.54 Å) and one longer (1.57 Å) P–O bond length. In the third P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with two FeO6 octahedra. The corner-sharing octahedra tilt angles range from 17–40°. There are a spread of P–O bond distances ranging from 1.53–1.57 Å. In the fourth P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with two equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 29–40°. There are a spread of P–O bond distances ranging from 1.53–1.55 Å. There are seventeen inequivalent O sites. In the first O site, O is bonded in a distorted bent 120 degrees geometry to one Fe and one P atom. In the second O site, O is bonded in a bent 120 degrees geometry to one Fe and one P atom. In the third O site, O is bonded in a bent 120 degrees geometry to one Fe and one P atom. In the fourth O site, O is bonded in a bent 120 degrees geometry to one P and one O atom. The O–O bond length is 1.23 Å. In the fifth O site, O is bonded in a bent 150 degrees geometry to one Fe and one P atom. In the sixth O site, O is bonded in a bent 150 degrees geometry to one Fe and one P atom. In the seventh O site, O is bonded in a single-bond geometry to one P atom. In the eighth O site, O is bonded in a single-bond geometry to one P atom. In the ninth O site, O is bonded in a linear geometry to one Fe and one P atom. In the tenth O site, O is bonded in a bent 150 degrees geometry to one Fe and one P atom. In the eleventh O site, O is bonded in a single-bond geometry to one P atom. In the twelfth O site, O is bonded in a single-bond geometry to one P atom. In the thirteenth O site, O is bonded in a bent 150 degrees geometry to one Fe and one P atom. In the fourteenth O site, O is bonded in a bent 150 degrees geometry to one Fe and one P atom. In the fifteenth O site, O is bonded in a single-bond geometry to one P atom. In the sixteenth O site, O is bonded in a single-bond geometry to one P atom. In the seventeenth O site, O is bonded in a single-bond geometry to one O atom.
FeI(NO)2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four FeI(NO)2 clusters. Fe3+ is bonded to two N1+ and two equivalent I1- atoms to form distorted edge-sharing FeI2N2 tetrahedra. Both Fe–N bond lengths are 1.79 Å. There are one shorter (2.71 Å) and one longer (2.72 Å) Fe–I bond lengths. There are two inequivalent N1+ sites. In the first N1+ site, N1+ is bonded in a distorted bent 150 degrees geometry to one Fe3+ and one O2- atom. The N–O bond length is 1.19 Å. In the second N1+ site, N1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The N–O bond length is 1.19 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one N1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one N1+ atom. I1- is bonded in a 2-coordinate geometry to two equivalent Fe3+ atoms.
(FeH8(SO6)2)2Zn(H2O)6 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of one FeH8(SO6)2 sheet oriented in the (0, 0, 1) direction and one zinc hexahydrate molecule. In the FeH8(SO6)2 sheet, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two SO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.97–2.09 Å. There are eight inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.66 Å) H–O bond length. In the second H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.65 Å) H–O bond length. In the third H1+ site, H1+ is bonded in a distorted single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to two O2- atoms. There is one shorter (1.00 Å) and one longer (1.71 Å) H–O bond length. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the sixth H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.64 Å) H–O bond length. In the seventh H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.00 Å) and one longer (1.68 Å) H–O bond length. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are two inequivalent S6+ sites. In the first S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share a cornercorner with one FeO6 octahedra. The corner-sharing octahedral tilt angles are 34°. There are a spread of S–O bond distances ranging from 1.47–1.51 Å. In the second S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share a cornercorner with one FeO6 octahedra. The corner-sharing octahedral tilt angles are 32°. There are a spread of S–O bond distances ranging from 1.48–1.51 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe3+ and one S6+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one H1+ and one S6+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one S6+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one S6+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe3+ and one S6+ atom. In the sixth O2- site, O2- is bonded in a single-bond geometry to one S6+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two H1+ and one S6+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two H1+ and one S6+ atom. In the ninth O2- site, O2- is bonded in a distorted water-like geometry to one Fe3+ and two H1+ atoms. In the tenth O2- site, O2- is bonded in a distorted water-like geometry to one Fe3+ and two H1+ atoms. In the eleventh O2- site, O2- is bonded in a distorted water-like geometry to one Fe3+ and two H1+ atoms. In the twelfth O2- site, O2- is bonded in a distorted water-like geometry to one Fe3+ and two H1+ atoms.
Fe2O3 crystallizes in the triclinic P1 space group. The structure is two-dimensional and consists of one Fe2O3 sheet oriented in the (1, 1, -1) direction. there are sixteen inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded in a 3-coordinate geometry to two Fe3+ and four O2- atoms. There are one shorter (2.07 Å) and one longer (2.08 Å) Fe–Fe bond lengths. There are a spread of Fe–O bond distances ranging from 2.01–2.55 Å. In the second Fe3+ site, Fe3+ is bonded in a 6-coordinate geometry to one Fe3+ and six O2- atoms. The Fe–Fe bond length is 2.05 Å. There are a spread of Fe–O bond distances ranging from 1.73–2.43 Å. In the third Fe3+ site, Fe3+ is bonded in a 3-coordinate geometry to two Fe3+ and five O2- atoms. The Fe–Fe bond length is 2.03 Å. There are a spread of Fe–O bond distances ranging from 2.01–2.54 Å. In the fourth Fe3+ site, Fe3+ is bonded in a distorted single-bond geometry to three O2- atoms. There are a spread of Fe–O bond distances ranging from 1.47–2.15 Å. In the fifth Fe3+ site, Fe3+ is bonded in a 3-coordinate geometry to five O2- atoms. There are a spread of Fe–O bond distances ranging from 1.50–2.22 Å. In the sixth Fe3+ site, Fe3+ is bonded in a 1-coordinate geometry to three O2- atoms. There are a spread of Fe–O bond distances ranging from 1.45–2.13 Å. In the seventh Fe3+ site, Fe3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Fe–O bond distances ranging from 1.80–2.25 Å. In the eighth Fe3+ site, Fe3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Fe–O bond distances ranging from 1.87–2.16 Å. In the ninth Fe3+ site, Fe3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Fe–O bond distances ranging from 1.52–2.18 Å. In the tenth Fe3+ site, Fe3+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Fe–O bond distances ranging from 1.82–2.25 Å. In the eleventh Fe3+ site, Fe3+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Fe–O bond distances ranging from 1.85–2.21 Å. In the twelfth Fe3+ site, Fe3+ is bonded in a 6-coordinate geometry to one Fe3+ and six O2- atoms. There are a spread of Fe–O bond distances ranging from 1.71–2.44 Å. In the thirteenth Fe3+ site, Fe3+ is bonded in a 2-coordinate geometry to two Fe3+ and eight O2- atoms. There are a spread of Fe–O bond distances ranging from 2.03–2.53 Å. In the fourteenth Fe3+ site, Fe3+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Fe–O bond distances ranging from 1.74–2.11 Å. In the fifteenth Fe3+ site, Fe3+ is bonded in a hexagonal planar geometry to six O2- atoms. There are a spread of Fe–O bond distances ranging from 1.76–2.04 Å. In the sixteenth Fe3+ site, Fe3+ is bonded in a 8-coordinate geometry to six O2- atoms. There are a spread of Fe–O bond distances ranging from 1.84–2.22 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to four Fe3+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to four Fe3+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to four Fe3+ atoms. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two Fe3+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to four Fe3+ atoms. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to three Fe3+ and one O2- atom. The O–O bond length is 2.17 Å. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to three Fe3+ atoms. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to three Fe3+ and one O2- atom. The O–O bond length is 2.32 Å. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to four Fe3+ and one O2- atom. The O–O bond length is 2.30 Å. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to three Fe3+ and three O2- atoms. There are one shorter (2.12 Å) and one longer (2.21 Å) O–O bond lengths. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to three Fe3+ atoms. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to four Fe3+ atoms. In the thirteenth O2- site, O2- is bonded in a 1-coordinate geometry to two Fe3+ and one O2- atom. In the fourteenth O2- site, O2- is bonded in a 2-coordinate geometry to four Fe3+ atoms. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to four Fe3+ atoms. In the sixteenth O2- site, O2- is bonded in a 3-coordinate geometry to three Fe3+ atoms. In the seventeenth O2- site, O2- is bonded in a 3-coordinate geometry to three Fe3+ and one O2- atom. The O–O bond length is 2.36 Å. In the eighteenth O2- site, O2- is bonded in a 1-coordinate geometry to two Fe3+ and one O2- atom. The O–O bond length is 2.15 Å. In the nineteenth O2- site, O2- is bonded in a 2-coordinate geometry to three Fe3+ atoms. In the twentieth O2- site, O2- is bonded in a 1-coordinate geometry to four Fe3+ and three O2- atoms. The O–O bond length is 2.21 Å. In the twenty-first O2- site, O2- is bonded in a 2-coordinate geometry to three Fe3+ and one O2- atom. In the twenty-second O2- site, O2- is bonded in a 1-coordinate geometry to four Fe3+ and three O2- atoms. In the twenty-third O2- site, O2- is bonded in a 4-coordinate geometry to four Fe3+ atoms. In the twenty-fourth O2- site, O2- is bonded in a 4-coordinate geometry to four Fe3+ atoms.
Fe3H6(SO7)2NH4 crystallizes in the trigonal R3m space group. The structure is two-dimensional and consists of three ammonium molecules and three Fe3H6(SO7)2 sheets oriented in the (0, 0, 1) direction. In each Fe3H6(SO7)2 sheet, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four equivalent FeO6 octahedra and corners with two SO4 tetrahedra. The corner-sharing octahedra tilt angles range from 45–46°. There are a spread of Fe–O bond distances ranging from 2.02–2.09 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are two inequivalent S2+ sites. In the first S2+ site, S2+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with three equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There is one shorter (1.47 Å) and three longer (1.50 Å) S–O bond length. In the second S2+ site, S2+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with three equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 49°. There is one shorter (1.47 Å) and three longer (1.50 Å) S–O bond length. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Fe3+ and one S2+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one S2+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Fe3+ and one H1+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Fe3+ and one H1+ atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one S2+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Fe3+ and one S2+ atom.
(Fe(SO4)2)2N2 crystallizes in the trigonal P321 space group. The structure is two-dimensional and consists of one ammonia molecule and one Fe(SO4)2 sheet oriented in the (0, 0, 1) direction. In the Fe(SO4)2 sheet, Fe3+ is bonded to six equivalent O2- atoms to form distorted FeO6 octahedra that share corners with six equivalent SO4 tetrahedra. All Fe–O bond lengths are 2.02 Å. S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with three equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 35°. There is one shorter (1.45 Å) and three longer (1.50 Å) S–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one S6+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe3+ and one S6+ atom.
FeC2(O2Cl)2C3H7NH3H2O crystallizes in the monoclinic P2_1/c space group. The structure is one-dimensional and consists of four trimethylazanium molecules; four water molecules; and two FeC2(O2Cl)2 ribbons oriented in the (0, 1, 0) direction. In each FeC2(O2Cl)2 ribbon, Fe3+ is bonded in an octahedral geometry to four O2- and two Cl1- atoms. There are a spread of Fe–O bond distances ranging from 2.08–2.15 Å. There are one shorter (2.28 Å) and one longer (2.29 Å) Fe–Cl bond lengths. There are two inequivalent C sites. In the first C site, C is bonded in a distorted bent 120 degrees geometry to two O2- atoms. There is one shorter (1.26 Å) and one longer (1.27 Å) C–O bond length. In the second C site, C is bonded in a distorted bent 120 degrees geometry to two O2- atoms. There is one shorter (1.26 Å) and one longer (1.27 Å) C–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to one Fe3+ and one C atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Fe3+ and one C atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one Fe3+ and one C atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Fe3+ and one C atom. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Fe3+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Fe3+ atom.
Fe3H6(SO7)2H3O crystallizes in the trigonal R3m space group. The structure is two-dimensional and consists of three hydrogen hydrate molecules and three Fe3H6(SO7)2 sheets oriented in the (0, 0, 1) direction. In each Fe3H6(SO7)2 sheet, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four equivalent FeO6 octahedra and corners with two SO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–49°. There are a spread of Fe–O bond distances ranging from 2.00–2.08 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are two inequivalent S6+ sites. In the first S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with three equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 48°. There is one shorter (1.47 Å) and three longer (1.50 Å) S–O bond length. In the second S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with three equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There is one shorter (1.47 Å) and three longer (1.50 Å) S–O bond length. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Fe3+ and one H1+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Fe3+ and one H1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one S6+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one S6+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Fe3+ and one S6+ atom. In the sixth O2- site, O2- is bonded in a bent 120 degrees geometry to one Fe3+ and one S6+ atom.
Buchwald examined samples of the IIIB iron Tambo Quemado (TAMQ) cut from the 130 kg main mass. He determined it had been artificially heated, at some time prior to being reported, in an attempt to obtain metal from it. Although the Widmanstatten structure appears relatively unaffected under macroscopic examination, microscopic study of etched sections reveals the effect of the heating. Taenite and plessite area boundaries are indistinct due to high temperature diffusion. Schreibersite, once present in significant amounts, has been melted. Schreibersites in the interior have resolidified in fine-grained eutectic textures surrounded by dark-etching metal rims supersaturated with phosphorus. Buchwald states that phosphate minerals were probably present originally, because graftonite, and its polymorph sarcopside (both essentially Fe3(PO4)2), are common in irons of the IIIB groups. Based on his metallographic study Buchwald estimates TAMQ was heated to 1000 C for about one hour. An interior sample from TAMQ was examined in order to determine what effect this unintended heating 'experiment' had upon the phosphate phases.
The Chemistry and Mineralogy (CheMin) instrument on the Mars Science Laboratory (MSL) Rover, Curiosity, analyzes samples collected in Gale Crater, Mars using X-ray diffraction (XRD). One site of interest is the Oudam drill sample that CheMin analyzed on sols 1362, 1365, and 1369, which contains ~3 wt% phyllosilicate. XRD analysis of this phyllosilicate suggests a 2:1 Fe3+-smectite, akin to nontronite.
Gale crater was selected as the landing site for the Mars Science Laboratory Curiosity rover because of orbital evidence for a variety of secondary minerals in the lower slopes of Aeolis Mons (aka Mount Sharp) that indicate changes in aqueous conditions over time. Distinct units demonstrate orbital spectral signatures of hematite, phyllosilicate (smectite), and sulfate minerals, which suggest that ancient aqueous environments in Gale crater varied in oxidation potential, pH, and water activity. Vera Rubin ridge (VRR) is the first of these units identified from orbit to have been studied by Curiosity. Orbital near-infrared data from VRR show a strong band at 860 nm indicative of hematite. Before Curiosity arrived at VRR, the hypotheses to explain the formation of hematite included (1) precipitation at a redox interface where aqueous Fe2+ was oxidized to Fe3+, and (2) acidic alteration of olivine in oxic fluids. Studying the composition and sedimentology of the rocks on VRR allow us to test and refine these hypotheses and flesh out the depositional and diagenetic history of the ridge. Here, we focus on the mineralogical results of four rock powders drilled from and immediately below VRR as determined by CheMin.