{
  "spore": "profile",
  "id": "mgs-1-mars-simulant",
  "spore_version": "0.2",
  "family": "regolith",
  "name": "MGS-1 Mars Global Simulant",
  "abbreviation": "MGS-1",
  "role": "Earth stand-in for Mars soil in tests",
  "category": "regolith",
  "type": "mars-simulants",
  "summary": "MGS-1 Mars Global Simulant is an open-standard powder that reproduces the mineral mix of the Rocknest windblown soil at Gale crater, Mars. Its December 2022 fact sheet gives an uncompressed bulk density of 1.29 g/cm3 and a median particle size of 60 μm, and lists 27.1 wt% anorthosite and 22.9 wt% glass-rich basalt as mixed. The 2019 paper that defines the standard (Cannon et al., Icarus 317) reports the same bulk density for its prototype, a mean grain size of 122 μm by volume, and a different bulk chemistry.\n",
  "best_for": "Ground tests of hardware and of in-situ resource utilization on a basaltic Mars analogue, where mineral mix and volatile content matter most (Cannon et al. 2019, Section 5.1)",
  "weakest_at": "Bulk chemistry: the fact sheet and the Cannon et al. prototype give different oxide values (SiO2 42.9 wt% against 50.8 wt%), so no single bulk chemistry is settled",
  "identity": {
    "formula": "Mixed mineral powder: anorthosite (plagioclase), glass-rich basalt, pyroxene, olivine, Mg-sulfate, ferrihydrite, hydrated silica, magnetite, anhydrite, Fe-carbonate and hematite",
    "designations": [],
    "source": "mgs1-spec-sheet",
    "where": "Mineralogy table, As mixed (wt%), 11 components"
  },
  "tags": {
    "environments": [
      "mars-surface"
    ],
    "stresses": [],
    "applications": [
      "rovers-and-surface-systems",
      "in-space-manufacturing"
    ]
  },
  "properties": [
    {
      "benchmark": "bulk_density",
      "label": "Uncompressed bulk density",
      "value": 1.29,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "state": "uncompressed bulk powder, as mixed",
        "basis": "value printed on the fact sheet"
      },
      "method": "Printed value on the fact sheet; Cannon et al. 2019 report the same 1.29 g/cm3 for their prototype (Section 4.1)",
      "status": "ground",
      "note": "Cannon et al. 2019 say they could not find a published density or porosity for Rocknest soil itself.",
      "source": "mgs1-spec-sheet",
      "where": "Header block, Uncompressed Bulk Density",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "angle_of_repose",
      "label": "Average angle of repose",
      "value": 38.9,
      "bound": "exact",
      "unit": "°",
      "scope": "material",
      "conditions": {
        "basis": "average angle of repose as printed; test method not stated"
      },
      "method": "Printed on the fact sheet, Geotechnical Properties block",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Geotechnical Properties, Avg Angle of Repose",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "angle_of_repose",
      "label": "Maximum angle of repose",
      "value": 43.6,
      "bound": "exact",
      "unit": "°",
      "scope": "material",
      "conditions": {
        "basis": "maximum angle of repose as printed; test method not stated"
      },
      "method": "Printed on the fact sheet, Geotechnical Properties block",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Geotechnical Properties, Max Angle of Repose",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "particle_size_mean",
      "label": "Mean particle size (fact sheet)",
      "value": 90,
      "bound": "exact",
      "unit": "μm",
      "scope": "material",
      "conditions": {
        "distribution": "volumetric, laser diffraction",
        "instrument": "CILAS 1190 laser diffraction particle size analyzer"
      },
      "method": "Printed on the fact sheet; the volumetric distribution slide names the CILAS 1190 analyzer",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Header block, Mean Particle Size; Volumetric Particle Size Distribution slide",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "particle_size_median",
      "label": "Median particle size (fact sheet)",
      "value": 60,
      "bound": "exact",
      "unit": "μm",
      "scope": "material",
      "conditions": {
        "distribution": "volumetric, laser diffraction",
        "instrument": "CILAS 1190 laser diffraction particle size analyzer"
      },
      "method": "Printed on the fact sheet header block",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Header block, Median Particle Size",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "particle_size_range",
      "label": "Particle size range (fact sheet)",
      "value": 0.04,
      "value_high": 600,
      "bound": "range",
      "unit": "μm",
      "scope": "material",
      "conditions": {
        "bound_note": "the fact sheet prints the lower limit as greater than 0.04 μm"
      },
      "method": "Printed range on the fact sheet",
      "status": "ground",
      "note": "The lower limit is printed as greater than 0.04 μm, so 0.04 μm is a bound, not a measured minimum.",
      "source": "mgs1-spec-sheet",
      "where": "Header block, Particle Size Range",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "particle_fraction_finer_than_53um",
      "label": "Fraction finer than 53 μm by mass (sieve)",
      "value": 3.6,
      "bound": "exact",
      "unit": "% by mass",
      "scope": "material",
      "conditions": {
        "method": "sieve analysis following ASTM E11 with RO-TAP RX-30 shaker",
        "basis": "mass"
      },
      "method": "Printed under Sieve Analysis; the fact sheet notes that sieving skews sizes larger because fines cling to coarse grains",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Sieve Analysis table, row 270 (53 µm), Finer by Mass column",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "particle_size_mean",
      "label": "Mean grain size by volume (Cannon prototype)",
      "value": 122,
      "bound": "exact",
      "unit": "μm",
      "scope": "material",
      "conditions": {
        "basis": "prototype sieved below 1 mm; volume mean",
        "medium": "isopropyl alcohol",
        "instrument": "Microtrac S3500 particle size analyzer",
        "replicates": "measured in triplicate"
      },
      "method": "Measured at Johnson Space Center ARES facilities (Section 3.3); the paper reports the mean by volume",
      "status": "ground",
      "note": "Different instrument and sample preparation from the fact sheet's 90 μm mean, so the two means are not directly comparable.",
      "source": "cannon2019",
      "where": "Section 4.1 (Physical properties), paragraph after Fig. 3",
      "source_detail": {
        "title": "Mars global simulant MGS-1: A Rocknest-based open standard for basaltic martian regolith simulants",
        "id": "doi:10.1016/j.icarus.2018.08.019 (Icarus 317, 470-478)",
        "url": "https://sciences.ucf.edu/class/wp-content/uploads/sites/23/2019/11/Cannon2019.pdf",
        "year": 2019,
        "kind": "paper",
        "license": "publisher copyright; cited, not reproduced"
      }
    },
    {
      "benchmark": "sio2",
      "label": "SiO2, XRF (fact sheet)",
      "value": 42.9,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "method": "XRF on fused bead, relative abundances, Hamilton Analytical Lab",
        "basis": "oxide wt%"
      },
      "method": "Printed in the Bulk Chemistry table as Oxide Wt.%",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Bulk Chemistry table, SiO2 row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "sio2",
      "label": "SiO2, XRF (Cannon prototype)",
      "value": 50.8,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "prototype MGS-1 simulant, measured by XRF in oxides mode at the UCF Materials Characterization Facility"
      },
      "method": "Measured by Cannon et al. (Section 3.3) and printed in Table 2, MGS-1 prototype column",
      "status": "ground",
      "note": "Disagrees with the fact sheet's 42.9 wt%. Cannon et al. attribute deviations from Rocknest mainly to the silicate chemistry used, with MgO and FeO most affected.",
      "source": "cannon2019",
      "where": "Table 2, MGS-1 prototype column, SiO2 row",
      "source_detail": {
        "title": "Mars global simulant MGS-1: A Rocknest-based open standard for basaltic martian regolith simulants",
        "id": "doi:10.1016/j.icarus.2018.08.019 (Icarus 317, 470-478)",
        "url": "https://sciences.ucf.edu/class/wp-content/uploads/sites/23/2019/11/Cannon2019.pdf",
        "year": 2019,
        "kind": "paper",
        "license": "publisher copyright; cited, not reproduced"
      }
    },
    {
      "benchmark": "mgo",
      "label": "MgO, XRF (fact sheet)",
      "value": 14.6,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "method": "XRF on fused bead, relative abundances, Hamilton Analytical Lab",
        "basis": "oxide wt%"
      },
      "method": "Printed in the Bulk Chemistry table as Oxide Wt.%",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Bulk Chemistry table, MgO row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "mgo",
      "label": "MgO, XRF (Cannon prototype)",
      "value": 16.7,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "prototype MGS-1 simulant, measured by XRF in oxides mode at the UCF Materials Characterization Facility"
      },
      "method": "Measured by Cannon et al. (Section 3.3) and printed in Table 2, MGS-1 prototype column",
      "status": "ground",
      "note": "Disagrees with the fact sheet's 14.6 wt%.",
      "source": "cannon2019",
      "where": "Table 2, MGS-1 prototype column, MgO row",
      "source_detail": {
        "title": "Mars global simulant MGS-1: A Rocknest-based open standard for basaltic martian regolith simulants",
        "id": "doi:10.1016/j.icarus.2018.08.019 (Icarus 317, 470-478)",
        "url": "https://sciences.ucf.edu/class/wp-content/uploads/sites/23/2019/11/Cannon2019.pdf",
        "year": 2019,
        "kind": "paper",
        "license": "publisher copyright; cited, not reproduced"
      }
    },
    {
      "benchmark": "feo",
      "label": "FeO, XRF (fact sheet)",
      "value": 11.2,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "method": "XRF on fused bead, relative abundances, Hamilton Analytical Lab",
        "basis": "oxide wt%"
      },
      "method": "Printed in the Bulk Chemistry table as Oxide Wt.%",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Bulk Chemistry table, FeO row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "feo",
      "label": "FeOT (total iron as FeO, Cannon prototype)",
      "value": 13.3,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "total iron expressed as FeO, prototype MGS-1 simulant"
      },
      "method": "Measured by Cannon et al. (Section 3.3) and printed in Table 2, MGS-1 prototype column",
      "status": "ground",
      "note": "Total iron as FeO in the paper; the fact sheet prints FeO. Disagrees with the fact sheet's 11.2 wt%.",
      "source": "cannon2019",
      "where": "Table 2, MGS-1 prototype column, FeOT row",
      "source_detail": {
        "title": "Mars global simulant MGS-1: A Rocknest-based open standard for basaltic martian regolith simulants",
        "id": "doi:10.1016/j.icarus.2018.08.019 (Icarus 317, 470-478)",
        "url": "https://sciences.ucf.edu/class/wp-content/uploads/sites/23/2019/11/Cannon2019.pdf",
        "year": 2019,
        "kind": "paper",
        "license": "publisher copyright; cited, not reproduced"
      }
    },
    {
      "benchmark": "al2o3",
      "label": "Al2O3, XRF (fact sheet)",
      "value": 12.8,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "method": "XRF on fused bead, relative abundances, Hamilton Analytical Lab",
        "basis": "oxide wt%"
      },
      "method": "Printed in the Bulk Chemistry table as Oxide Wt.%",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Bulk Chemistry table, Al2O3 row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "al2o3",
      "label": "Al2O3, XRF (Cannon prototype)",
      "value": 8.9,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "prototype MGS-1 simulant, measured by XRF in oxides mode at the UCF Materials Characterization Facility"
      },
      "method": "Measured by Cannon et al. (Section 3.3) and printed in Table 2, MGS-1 prototype column",
      "status": "ground",
      "note": "Disagrees with the fact sheet's 12.8 wt%.",
      "source": "cannon2019",
      "where": "Table 2, MGS-1 prototype column, Al2O3 row",
      "source_detail": {
        "title": "Mars global simulant MGS-1: A Rocknest-based open standard for basaltic martian regolith simulants",
        "id": "doi:10.1016/j.icarus.2018.08.019 (Icarus 317, 470-478)",
        "url": "https://sciences.ucf.edu/class/wp-content/uploads/sites/23/2019/11/Cannon2019.pdf",
        "year": 2019,
        "kind": "paper",
        "license": "publisher copyright; cited, not reproduced"
      }
    },
    {
      "benchmark": "loss_on_ignition",
      "label": "Loss on ignition (LOI), fact sheet",
      "value": 5.3,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "loss on ignition as footnoted in the Bulk Chemistry table"
      },
      "method": "Printed on the fact sheet, footnote LOI",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Bulk Chemistry table, LOI row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "mass_loss_30_500c",
      "label": "Mass loss on heating, 30 to 500 °C (prototype)",
      "value": 3.9,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "range": "30 to 500 °C",
        "sample": "MGS-1 prototype, not the fact-sheet product",
        "basis": "relative mass"
      },
      "method": "Thermogravimetric analysis, reported by Cannon et al. (Section 4.4)",
      "status": "ground",
      "source": "cannon2019",
      "where": "Section 4.4 (Thermogravimetry), first paragraph",
      "source_detail": {
        "title": "Mars global simulant MGS-1: A Rocknest-based open standard for basaltic martian regolith simulants",
        "id": "doi:10.1016/j.icarus.2018.08.019 (Icarus 317, 470-478)",
        "url": "https://sciences.ucf.edu/class/wp-content/uploads/sites/23/2019/11/Cannon2019.pdf",
        "year": 2019,
        "kind": "paper",
        "license": "publisher copyright; cited, not reproduced"
      }
    },
    {
      "benchmark": "water_content_30_500c",
      "label": "Water (H2O) equivalent from mass loss, 30 to 500 °C",
      "value": 3.2,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "H2O-related mass loss expressed as wt% of MGS-1",
        "assumption": "siderite assumed to decompose completely",
        "sample": "MGS-1 prototype"
      },
      "method": "Value stated by Cannon et al. from the thermogravimetry data (Section 4.4)",
      "status": "ground",
      "source": "cannon2019",
      "where": "Section 4.4 (Thermogravimetry), paragraph after the 3.9% figure",
      "source_detail": {
        "title": "Mars global simulant MGS-1: A Rocknest-based open standard for basaltic martian regolith simulants",
        "id": "doi:10.1016/j.icarus.2018.08.019 (Icarus 317, 470-478)",
        "url": "https://sciences.ucf.edu/class/wp-content/uploads/sites/23/2019/11/Cannon2019.pdf",
        "year": 2019,
        "kind": "paper",
        "license": "publisher copyright; cited, not reproduced"
      }
    },
    {
      "benchmark": "so3_content",
      "label": "Sulfur trioxide (volatile), XRF",
      "value": 1.27,
      "bound": "lower",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "bound_note": "printed as at least (≥)",
        "method": "XRF, volatiles"
      },
      "method": "Printed in the Volatiles table on the fact sheet",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Volatiles table, SO3 row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "fluorine_content",
      "label": "Fluorine (volatile), XRF",
      "value": 0.1,
      "bound": "lower",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "bound_note": "printed as at least (≥)",
        "method": "XRF, volatiles"
      },
      "method": "Printed in the Volatiles table on the fact sheet",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Volatiles table, F row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "chlorine_content",
      "label": "Chlorine (volatile), XRF",
      "value": 0.005,
      "bound": "lower",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "bound_note": "printed as at least (≥)",
        "method": "XRF, volatiles"
      },
      "method": "Printed in the Volatiles table on the fact sheet",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Volatiles table, Cl row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "mineral_fraction",
      "label": "Anorthosite (plagioclase), as mixed",
      "value": 27.1,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "as mixed, share of the mineral components"
      },
      "method": "Printed in the Mineralogy table. The fact sheet calls this anorthosite; Cannon et al. Table 1 calls it plagioclase at the same 27.1 wt%",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Mineralogy table, Anorthosite row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "mineral_fraction",
      "label": "Glass-rich basalt (basaltic glass), as mixed",
      "value": 22.9,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "as mixed, share of the mineral components"
      },
      "method": "Printed in the Mineralogy table; Cannon et al. Table 1 gives basaltic glass at the same 22.9 wt%",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Mineralogy table, Glass-rich basalt row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "mineral_fraction",
      "label": "Pyroxene, as mixed",
      "value": 20.3,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "as mixed, share of the mineral components"
      },
      "method": "Printed in the Mineralogy table; Cannon et al. Table 1 gives the same 20.3 wt%",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Mineralogy table, Pyroxene row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "mineral_fraction",
      "label": "Olivine, as mixed",
      "value": 13.7,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "as mixed, share of the mineral components"
      },
      "method": "Printed in the Mineralogy table; Cannon et al. Table 1 gives the same 13.7 wt%",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Mineralogy table, Olivine row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "mineral_fraction",
      "label": "Mg-sulfate, as mixed",
      "value": 4,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "as mixed, share of the mineral components"
      },
      "method": "Printed in the Mineralogy table; Cannon et al. Table 1 gives the same 4.0 wt%",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Mineralogy table, Mg-sulfate row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "mineral_fraction",
      "label": "Ferrihydrite, as mixed (fact sheet)",
      "value": 3.5,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "as mixed, share of the mineral components"
      },
      "method": "Printed in the Mineralogy table; Cannon et al. Table 1 gives a different value (see next entry)",
      "status": "ground",
      "note": "Disagrees with Cannon et al. Table 1 (1.7 wt%).",
      "source": "mgs1-spec-sheet",
      "where": "Mineralogy table, Ferrihydrite row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "mineral_fraction",
      "label": "Ferrihydrite, Cannon et al. Table 1 prototype recipe",
      "value": 1.7,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "prototype recipe, share of the mineral components"
      },
      "method": "Printed in Table 1 of Cannon et al. 2019",
      "status": "ground",
      "note": "Disagrees with the fact sheet's 3.5 wt%.",
      "source": "cannon2019",
      "where": "Table 1, Ferrihydrite row",
      "source_detail": {
        "title": "Mars global simulant MGS-1: A Rocknest-based open standard for basaltic martian regolith simulants",
        "id": "doi:10.1016/j.icarus.2018.08.019 (Icarus 317, 470-478)",
        "url": "https://sciences.ucf.edu/class/wp-content/uploads/sites/23/2019/11/Cannon2019.pdf",
        "year": 2019,
        "kind": "paper",
        "license": "publisher copyright; cited, not reproduced"
      }
    },
    {
      "benchmark": "mineral_fraction",
      "label": "Hydrated silica, as mixed (fact sheet)",
      "value": 3,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "as mixed, share of the mineral components"
      },
      "method": "Printed in the Mineralogy table; Cannon et al. Table 1 gives a different value (see next entry)",
      "status": "ground",
      "note": "Disagrees with Cannon et al. Table 1 (5.0 wt%, labelled hydrated silica (opal)).",
      "source": "mgs1-spec-sheet",
      "where": "Mineralogy table, Hydrated silica row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "mineral_fraction",
      "label": "Hydrated silica (opal), Cannon et al. Table 1 prototype recipe",
      "value": 5,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "prototype recipe, share of the mineral components"
      },
      "method": "Printed in Table 1 of Cannon et al. 2019, amorphous phases",
      "status": "ground",
      "note": "Disagrees with the fact sheet's 3.0 wt%.",
      "source": "cannon2019",
      "where": "Table 1, Hydrated Silica (Opal) row",
      "source_detail": {
        "title": "Mars global simulant MGS-1: A Rocknest-based open standard for basaltic martian regolith simulants",
        "id": "doi:10.1016/j.icarus.2018.08.019 (Icarus 317, 470-478)",
        "url": "https://sciences.ucf.edu/class/wp-content/uploads/sites/23/2019/11/Cannon2019.pdf",
        "year": 2019,
        "kind": "paper",
        "license": "publisher copyright; cited, not reproduced"
      }
    },
    {
      "benchmark": "mineral_fraction",
      "label": "Magnetite, as mixed",
      "value": 1.9,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "as mixed, share of the mineral components"
      },
      "method": "Printed in the Mineralogy table; Cannon et al. Table 1 gives the same 1.9 wt%",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Mineralogy table, Magnetite row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "mineral_fraction",
      "label": "Anhydrite, as mixed (fact sheet)",
      "value": 1.7,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "as mixed, share of the mineral components"
      },
      "method": "Printed in the Mineralogy table; Cannon et al. Table 1 gives a different value (see next entry)",
      "status": "ground",
      "note": "Disagrees with Cannon et al. Table 1 (0.9 wt%).",
      "source": "mgs1-spec-sheet",
      "where": "Mineralogy table, Anhydrite row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "mineral_fraction",
      "label": "Anhydrite, Cannon et al. Table 1 prototype recipe",
      "value": 0.9,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "prototype recipe, share of the mineral components"
      },
      "method": "Printed in Table 1 of Cannon et al. 2019",
      "status": "ground",
      "note": "Disagrees with the fact sheet's 1.7 wt%.",
      "source": "cannon2019",
      "where": "Table 1, Anhydrite row",
      "source_detail": {
        "title": "Mars global simulant MGS-1: A Rocknest-based open standard for basaltic martian regolith simulants",
        "id": "doi:10.1016/j.icarus.2018.08.019 (Icarus 317, 470-478)",
        "url": "https://sciences.ucf.edu/class/wp-content/uploads/sites/23/2019/11/Cannon2019.pdf",
        "year": 2019,
        "kind": "paper",
        "license": "publisher copyright; cited, not reproduced"
      }
    },
    {
      "benchmark": "mineral_fraction",
      "label": "Fe-carbonate (siderite), as mixed",
      "value": 1.4,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "as mixed, share of the mineral components"
      },
      "method": "Printed in the Mineralogy table; Cannon et al. Table 1 gives the same 1.4 wt%, named Fe-carbonated there",
      "status": "ground",
      "source": "mgs1-spec-sheet",
      "where": "Mineralogy table, Fe-carbonate row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "mineral_fraction",
      "label": "Hematite, as mixed (fact sheet)",
      "value": 0.5,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "as mixed, share of the mineral components"
      },
      "method": "Printed in the Mineralogy table; Cannon et al. Table 1 gives a different value (see next entry)",
      "status": "ground",
      "note": "Disagrees with Cannon et al. Table 1 (1.1 wt%).",
      "source": "mgs1-spec-sheet",
      "where": "Mineralogy table, Hematite row",
      "source_detail": {
        "title": "MGS-1 Mars Global Simulant | Fact Sheet",
        "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
        "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "publisher-supplied; cited, not reproduced"
      }
    },
    {
      "benchmark": "mineral_fraction",
      "label": "Hematite, Cannon et al. Table 1 prototype recipe",
      "value": 1.1,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "prototype recipe, share of the mineral components"
      },
      "method": "Printed in Table 1 of Cannon et al. 2019",
      "status": "ground",
      "note": "Disagrees with the fact sheet's 0.5 wt%.",
      "source": "cannon2019",
      "where": "Table 1, Hematite row",
      "source_detail": {
        "title": "Mars global simulant MGS-1: A Rocknest-based open standard for basaltic martian regolith simulants",
        "id": "doi:10.1016/j.icarus.2018.08.019 (Icarus 317, 470-478)",
        "url": "https://sciences.ucf.edu/class/wp-content/uploads/sites/23/2019/11/Cannon2019.pdf",
        "year": 2019,
        "kind": "paper",
        "license": "publisher copyright; cited, not reproduced"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Heating from 30 to 500 °C (MGS-1 prototype)",
      "headline": "The prototype loses 3.9% of its mass on heating from 30 to 500 °C.",
      "effect": "Cannon et al. report 3.9% relative mass loss over 30 to 500 °C and state that the water-related part corresponds to 3.2 wt% of MGS-1, assuming the siderite decomposes completely. They also report a sharp CO2 release from siderite breakdown and SO2 and O2 release near 950 °C from Mg-sulfate breakdown.",
      "rating": "moderate",
      "conditions": {
        "method": "thermogravimetry with evolved-gas analysis",
        "sample": "MGS-1 prototype, not the fact-sheet product"
      },
      "source": "cannon2019",
      "where": "Section 4.4 (Thermogravimetry)"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "The fact sheet names dust inhalation as the primary hazard and advises a respirator in dusty conditions.",
        "ghs": [],
        "source": "mgs1-spec-sheet",
        "where": "Safety block, page 1"
      },
      {
        "text": "The fact sheet refers readers to a separate safety data sheet for details. That sheet is not in the sources held, so no GHS classification is recorded here.",
        "ghs": [],
        "source": "mgs1-spec-sheet",
        "where": "Safety block, page 1"
      },
      {
        "text": "Sodium metasilicate, the binder named in the Cannon et al. prototype recipe, is classed in the Gelest SDS (CAS 6834-92-0) with hazard statements H302 (harmful if swallowed), H314 (causes severe skin burns and eye damage) and H335 (may cause respiratory irritation). The SDS signal word is Danger. The SDS covers the pure chemical, not MGS-1.",
        "ghs": [
          "H302",
          "H314",
          "H335"
        ],
        "source": "gelest-sds",
        "where": "Hazard statements (GHS-US) and Signal word lines"
      }
    ],
    "failure_risks": [],
    "side_effects": [
      {
        "text": "On heating the prototype, Cannon et al. report a broad water release, a sharp CO2 release from siderite breakdown, and SO2 and O2 release near 950 °C from Mg-sulfate breakdown.",
        "affects": "Gas analysis and furnace or oven exhaust during heating tests",
        "source": "cannon2019",
        "where": "Section 4.4 (Thermogravimetry)"
      }
    ],
    "handling": [
      {
        "text": "Wear a respirator in dusty conditions (fact sheet safety note).",
        "source": "mgs1-spec-sheet",
        "where": "Safety block, page 1"
      },
      {
        "text": "Cannon et al. made prototypes by drying a paste in a microwave oven, then grinding, mixing and sieving below 1 mm. The paper says the sieve size is adjustable and is not an inherent property of the simulant.",
        "source": "cannon2019",
        "where": "Section 3.2 (Simulant preparation)"
      }
    ],
    "mitigations": []
  },
  "uses": [
    {
      "application": "rovers-and-surface-systems",
      "device": "Ground hardware testing",
      "example": "Cannon et al. say researchers and engineers rely on terrestrial simulants to test future hardware, and that MGS-1 simulants are appropriate for testing flight hardware.",
      "source": "cannon2019",
      "where": "Abstract; Section 5.1 (Applications)"
    },
    {
      "application": "in-space-manufacturing",
      "device": "In-situ resource utilization (ISRU) technology development",
      "example": "Cannon et al. list ISRU technology development among the applications where MGS-1 simulants are most recommended, because mineralogy and volatile contents are important controlling factors.",
      "source": "cannon2019",
      "where": "Section 5.1 (Applications)"
    }
  ],
  "supply": [
    {
      "subject": "MGS-1 simulant (the product)",
      "abundance": "Not applicable: a manufactured mix of Earth minerals, not a mined commodity",
      "producers": [],
      "critical_lists": [],
      "recycling": "Not found in the sources held.",
      "substitutes": [],
      "source": "cannon2019",
      "where": "Abstract"
    },
    {
      "subject": "MGS-1 simulant (current supplier)",
      "abundance": "Not applicable",
      "producers": [],
      "critical_lists": [],
      "recycling": "Not found in the sources held.",
      "substitutes": [],
      "source": "ucf-mgs1",
      "where": "MGS-1 Mars Global Simulant section (read as page text)"
    },
    {
      "subject": "Mineral feedstock (plagioclase, pyroxene, olivine)",
      "abundance": "Not found in the sources held",
      "producers": [],
      "critical_lists": [],
      "recycling": "Not found in the sources held.",
      "substitutes": [],
      "source": "cannon2019",
      "where": "Section 3.1"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "MGS-1 Mars Global Simulant | Fact Sheet (December 2022)",
      "type": "datasheet",
      "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
      "year": 2022
    },
    {
      "title": "Mars global simulant MGS-1: A Rocknest-based open standard for basaltic martian regolith simulants (Icarus 317, 470-478)",
      "type": "paper",
      "url": "https://sciences.ucf.edu/class/wp-content/uploads/sites/23/2019/11/Cannon2019.pdf",
      "year": 2019
    },
    {
      "title": "Sodium metasilicate, safety data sheet (Gelest product SIS6982.0, CAS 6834-92-0)",
      "type": "sds",
      "url": "https://www.gelest.com/wp-content/uploads/product_msds/SIS6982.0-msds.pdf"
    },
    {
      "title": "Chemistry, mineralogy, and grain properties at Namib and High dunes, Bagnold dune field, Gale crater, Mars: A synthesis of Curiosity rover observations",
      "type": "paper",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC5815393/",
      "year": 2017
    },
    {
      "title": "Mineralogy of Eolian Sands at Gale Crater",
      "type": "paper",
      "url": "https://ntrs.nasa.gov/citations/20160002646",
      "year": 2016
    },
    {
      "title": "First X-Ray Diffraction Results from Mars Science Laboratory: Mineralogy of Rocknest Aeolian Bedform at Gale Crater (LPSC 2013 abstract)",
      "type": "paper",
      "url": "https://ntrs.nasa.gov/citations/20130009935",
      "year": 2013
    }
  ],
  "gaps": [
    "The fact sheet and the Cannon et al. 2019 paper were read as full text. The UCF simulant page was read as page text in this run, so its production-status statement is quoted, not paraphrased.",
    "The fact sheet's safety data sheet is not in the sources held. No GHS classification, toxicology, storage rule or failure-mode data for MGS-1 is recorded.",
    "No humidity, UV, long-term storage or ageing data for the simulant were found in the sources held.",
    "Cannon et al. 2019 say no published density or porosity was found for the Rocknest soil itself. Porosity and specific surface of the simulant were not found.",
    "The fact sheet and Cannon et al. 2019 disagree on the four oxides listed side by side (SiO2, MgO, FeO, Al2O3) and on four minor minerals (ferrihydrite, hydrated silica, anhydrite, hematite). Both values are listed; neither is resolved. Other oxides from the fact sheet's Bulk Chemistry table are not transcribed.",
    "The fact sheet's trace-element table (Ni, Cr, V and others) and its reflectance and FTIR spectra are not transcribed here.",
    "Particle-size methods differ: the fact sheet uses CILAS 1190 laser diffraction and sieving, and Cannon et al. use a Microtrac S3500. The two mean sizes are not directly comparable.",
    "Feedstock shares by country and critical-mineral status for the plagioclase, pyroxene and olivine sources were not found in the sources held. The USGS and EU critical-mineral lists were not checked for this profile.",
    "Five further sources were read in this run: the JPL Rocknest wheel-scuff caption, the NTRS 2016 Rocknest eolian-sand abstract, the 2017 JGR Planets Namib and High dunes paper, the Gelest sodium metasilicate SDS and the NTRS 2013 Bish et al. Rocknest abstract. The Achilles et al. 2017 Rocknest mineralogy paper that Cannon et al. cite was not opened.",
    "The NTRS 2013 Bish et al. abstract does not print the Rocknest phase values, so no Rocknest CheMin phase values are transcribed.",
    "The Space Resource Technologies product page returned HTTP 429 on every attempt in this run, so its price and stock status are not recorded.",
    "The PubChem record for sodium metasilicate could not be opened (browser check). The binder hazard entry therefore comes from the Gelest SDS for the pure chemical, not from MGS-1 or PubChem.",
    "Property names not in spores/property-canon.yaml, used as short snake_case names: bulk_density, angle_of_repose, particle_size_mean, particle_size_median, particle_size_range, particle_fraction_finer_than_53um, sio2, mgo, feo, al2o3, loss_on_ignition, mass_loss_30_500c, water_content_30_500c, so3_content, fluorine_content, chlorine_content and mineral_fraction."
  ],
  "story": {
    "why": "MGS-1 is an open-standard simulant of basaltic Martian regolith. Its mineral recipe follows the quantitative mineralogy of the Rocknest windblown soil that the Curiosity rover analysed in Gale crater. Cannon et al. say earlier Mars simulants sacrificed accuracy for convenience and had poor documentation, and that JSC Mars-1 and the Mojave Mars Simulant are no longer available outside NASA. They publish the recipe and production method so that other groups can recreate the simulant. The Rocknest sample was an eolian sand deposit, which the NASA abstract calls the Rocknest \"sand shadow\" (Achilles et al. 2016, NTRS 20160002646). Curiosity cut a wheel scuff mark into a wind-formed ripple there so researchers could examine the particle-size distribution of the ripple material (JPL image PIA16205). A 2017 JGR Planets study of the Namib and High dunes reports that Bagnold and Rocknest mineralogy are similar, with plagioclase, olivine and pyroxenes in similar proportions (PMC5815393).",
    "uses": [
      {
        "where": "Hardware testing",
        "line": "Cannon et al. say researchers and engineers rely on terrestrial simulants to test future hardware, and that MGS-1 simulants are appropriate for testing flight hardware."
      },
      {
        "where": "In-situ resource utilization",
        "line": "Cannon et al. list ISRU technology development among the applications where MGS-1 simulants are most recommended, because mineralogy and volatile contents are important controlling factors."
      }
    ],
    "can_do": [
      {
        "label": "Bulk density",
        "line": "The uncompressed bulk density is 1.29 g/cm3 per the fact sheet, and Cannon et al. report the same value for their prototype.",
        "benchmark": "bulk_density",
        "scope": "material"
      },
      {
        "label": "Flow behaviour",
        "line": "The fact sheet gives an average angle of repose of 38.9° and a maximum of 43.6°.",
        "benchmark": "angle_of_repose",
        "scope": "material"
      },
      {
        "label": "Particle size",
        "line": "The fact sheet gives a mean particle size of 90 μm and a median of 60 μm from laser diffraction. Cannon et al.'s prototype has a mean of 122 μm by volume, measured with a different instrument.",
        "benchmark": "particle_size_median",
        "scope": "material"
      },
      {
        "label": "Water on heating",
        "line": "Heated from 30 to 500 °C, the prototype released water equal to 3.2 wt% of MGS-1 (Cannon et al. 2019, Section 4.4).",
        "benchmark": "water_content_30_500c",
        "scope": "material"
      },
      {
        "label": "Volatile sulfur",
        "line": "The fact sheet gives SO3 of at least 1.27 wt%, measured by XRF.",
        "benchmark": "so3_content",
        "scope": "material"
      }
    ],
    "compare": "Cannon et al. say earlier Mars simulants did not superficially match Mars in spectral or bulk chemical properties, and that JSC Mars-1 has an unrealistically high water content from its heating test. MGS-1 is designed as a mineralogical match to Rocknest instead. The prototype's bulk density of 1.29 g/cm3 falls inside the range the paper gives for the Pathfinder landing site (Section 4.1). The fact sheet and the Cannon prototype disagree on bulk chemistry, with SiO2 at 42.9 wt% on the fact sheet and 50.8 wt% in the prototype, so use the mineral recipe for chemistry-sensitive work and check the oxide values for the product you buy.",
    "compare_rows": [
      {
        "label": "Bulk density",
        "benchmark": "bulk_density",
        "scope": "material"
      },
      {
        "label": "Median particle size",
        "benchmark": "particle_size_median",
        "scope": "material"
      },
      {
        "label": "Angle of repose (average)",
        "benchmark": "angle_of_repose",
        "scope": "material"
      }
    ],
    "handling": [
      "Wear a respirator where there is dust. The fact sheet names dust inhalation as the primary hazard.",
      "Store it as the supplier's safety data sheet directs. That sheet is not in the sources held, so no storage rule is recorded here.",
      "Heating releases water, CO2, SO2 and O2 in the Cannon et al. tests. Plan the exhaust for that."
    ],
    "good_for": [
      "Hardware and ISRU tests where mineralogy and volatile content matter. Cannon et al. recommend MGS-1 for those uses.",
      "Tests that need a documented, reproducible recipe. Cannon et al. publish the recipe and production method."
    ],
    "watch_out": [
      "Bulk chemistry: the fact sheet and the Cannon prototype disagree (SiO2 42.9 wt% against 50.8 wt%; MgO 14.6 wt% against 16.7 wt%).",
      "Four minor minerals (ferrihydrite, hydrated silica, anhydrite and hematite) differ between the fact sheet and Cannon et al. Table 1.",
      "Mean particle size: 90 μm from the fact sheet's laser method, against 122 μm by volume in the Cannon prototype.",
      "The Cannon values come from a lab-made prototype. The commercial product may differ."
    ],
    "verdict": "MGS-1 is a published, open recipe for basaltic Martian regolith with sourced density, particle-size and mineral-mix values. Its bulk chemistry and four minor mineral fractions differ between the fact sheet and the 2019 paper, so state which source you use for each number.",
    "recipe": {
      "line": "MGS-1 is a mixture of mineral powders, not one compound. The fact sheet lists 11 components as mixed, in weight percent, which together make up the whole mix. Cannon et al. made their prototypes by mixing plagioclase, pyroxene, olivine, basaltic glass and magnetite with water and a sodium metasilicate binder, drying the paste into hard cobbles, grinding the cobbles and mixing them with the secondary phases.",
      "parts": [
        {
          "name": "Anorthosite (plagioclase)",
          "role": "Largest crystalline component. The fact sheet calls it anorthosite; Cannon et al. call it plagioclase.",
          "share_percent": 27.1
        },
        {
          "name": "Glass-rich basalt (basaltic glass)",
          "role": "Amorphous basaltic glass, an X-ray amorphous phase in the mix.",
          "share_percent": 22.9
        },
        {
          "name": "Pyroxene",
          "role": "Crystalline silicate. Cannon et al. used a bronzite-variety pyroxene from Brazil.",
          "share_percent": 20.3
        },
        {
          "name": "Olivine",
          "role": "Crystalline silicate. Cannon et al. used highly forsteritic San Carlos olivine.",
          "share_percent": 13.7
        },
        {
          "name": "Mg-sulfate",
          "role": "Sulfate. Its breakdown releases SO2 and O2 near 950 °C on heating.",
          "share_percent": 4
        },
        {
          "name": "Ferrihydrite",
          "role": "Iron oxyhydroxide. Cannon et al. say ferrihydrite and hematite act as strong pigments. Table 1 gives 1.7 wt%.",
          "share_percent": 3.5
        },
        {
          "name": "Hydrated silica",
          "role": "Secondary phase. Cannon et al. Table 1 lists it as hydrated silica (opal) at 5.0 wt%.",
          "share_percent": 3
        },
        {
          "name": "Magnetite",
          "role": "Magnetic iron oxide. Cannon et al. say magnetite matters for the magnetic properties.",
          "share_percent": 1.9
        },
        {
          "name": "Anhydrite",
          "role": "Sulfate. Cannon et al. use anhydrite for sulfur content. Table 1 gives 0.9 wt%.",
          "share_percent": 1.7
        },
        {
          "name": "Fe-carbonate (siderite)",
          "role": "Iron carbonate. Its breakdown gives a sharp CO2 release on heating.",
          "share_percent": 1.4
        },
        {
          "name": "Hematite",
          "role": "Iron oxide and pigment. Cannon et al. Table 1 gives 1.1 wt%.",
          "share_percent": 0.5
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The fact sheet's only stated hazard is dust inhalation. The sources held give no GHS classification or toxicology for MGS-1 itself.",
        "points": [
          {
            "label": "The powder",
            "line": "The fact sheet names dust inhalation as the primary hazard and advises a respirator in dusty conditions. It refers to a separate safety data sheet for details, which is not in the sources held."
          },
          {
            "label": "Fine fraction",
            "line": "The fact sheet gives 3.6% by mass finer than 53 μm."
          }
        ],
        "level": 0,
        "verdict": "Dust is the stated hazard; use a respirator."
      },
      {
        "title": "If the simulant is heated",
        "lead": "These results come from laboratory heating of the Cannon et al. prototype, not from field incidents.",
        "points": [
          {
            "label": "Mass loss",
            "line": "The prototype lost 3.9% of its mass between 30 and 500 °C. Cannon et al. state that 3.2 wt% of MGS-1 is water-related loss, assuming the siderite decomposes completely."
          },
          {
            "label": "Gas release",
            "line": "Cannon et al. report a sharp CO2 release from siderite breakdown, and SO2 and O2 release near 950 °C from Mg-sulfate breakdown."
          }
        ]
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Storage",
            "line": "The sources held give no storage rule for MGS-1. The fact sheet refers to its safety data sheet, which is not in the sources held."
          },
          {
            "label": "Dust control",
            "line": "The fact sheet advises a respirator in dusty conditions."
          }
        ]
      }
    ]
  },
  "updated": "2026-11-01",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 37,
    "unreachable": 0,
    "caveats": 1,
    "note": "Written by an AI assistant on 2026-11-01 from the December 2022 fact sheet and the Cannon et al. 2019 PDF, both read as text. The UCF page was read as page text and used for supplier status. Deepened in a later run with five more sources (JPL PIA16205, NTRS 20160002646, NTRS 20130009935, a 2017 JGR Planets paper on the Namib and High dunes, and the Gelest sodium metasilicate SDS for the binder hazards); the quality bar now passes. verify-values found all 37 values in the cited source text (0 not found)."
  },
  "sources": {
    "mgs1-spec-sheet": {
      "title": "MGS-1 Mars Global Simulant | Fact Sheet",
      "id": "Fact sheet, December 2022 (PDF hosted on sshade.eu)",
      "url": "https://www.sshade.eu/file/2023/06/10/686b4bf4-0361-5d31-a051-f244efd51649/mgs-1-spec-sheet-Dec2022.pdf",
      "year": 2022,
      "kind": "datasheet",
      "license": "publisher-supplied; cited, not reproduced"
    },
    "cannon2019": {
      "title": "Mars global simulant MGS-1: A Rocknest-based open standard for basaltic martian regolith simulants",
      "id": "doi:10.1016/j.icarus.2018.08.019 (Icarus 317, 470-478)",
      "url": "https://sciences.ucf.edu/class/wp-content/uploads/sites/23/2019/11/Cannon2019.pdf",
      "year": 2019,
      "kind": "paper",
      "license": "publisher copyright; cited, not reproduced"
    },
    "ucf-mgs1": {
      "title": "MGS-1 Mars Global Simulant (UCF simulant page)",
      "id": "University of Central Florida, class simulant page",
      "url": "https://sciences.ucf.edu/class/simulant_marsglobal/",
      "kind": "web",
      "license": "web page; cited, not reproduced"
    },
    "jpl-rocknest-scuff": {
      "title": "Wheel scuff mark at Rocknest (JPL image PIA16205)",
      "id": "NASA JPL image PIA16205",
      "url": "https://www.jpl.nasa.gov/images/pia16205-wheel-scuff-mark-at-rocknest",
      "year": 2012,
      "kind": "web"
    },
    "ntrs-eolian-2016": {
      "title": "Mineralogy of Eolian Sands at Gale Crater",
      "id": "NASA NTRS 20160002646 (Achilles, Vaniman, Blake et al., 2016 abstract)",
      "url": "https://ntrs.nasa.gov/citations/20160002646",
      "year": 2016,
      "kind": "paper"
    },
    "namib-2017": {
      "title": "Chemistry, mineralogy, and grain properties at Namib and High dunes, Bagnold dune field, Gale crater, Mars: A synthesis of Curiosity rover observations",
      "id": "J Geophys Res Planets 122(12), 2510-2543; PMC5815393",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC5815393/",
      "year": 2017,
      "kind": "paper"
    },
    "gelest-sds": {
      "title": "Sodium metasilicate, safety data sheet (Gelest product SIS6982.0, CAS 6834-92-0)",
      "id": "Gelest SIS6982.0 SDS, CAS 6834-92-0",
      "url": "https://www.gelest.com/wp-content/uploads/product_msds/SIS6982.0-msds.pdf",
      "kind": "datasheet"
    },
    "ntrs-bish-2013": {
      "title": "First X-Ray Diffraction Results from Mars Science Laboratory: Mineralogy of Rocknest Aeolian Bedform at Gale Crater (LPSC 2013 abstract)",
      "id": "NASA NTRS 20130009935 (Bish, Blake, Vaniman et al., 2013)",
      "url": "https://ntrs.nasa.gov/citations/20130009935",
      "year": 2013,
      "kind": "paper"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/mgs-1-mars-simulant/"
}