{
  "spore": "profile",
  "id": "ruthenium",
  "spore_version": "0.2",
  "family": "precious-metals",
  "name": "Ruthenium",
  "abbreviation": "Ru",
  "role": "hard platinum-group metal for chip interconnects and contacts",
  "category": "metals",
  "type": "precious-metals",
  "summary": "Ruthenium is the pure metal Ru, atomic number 44, a hard and dense platinum-group metal. Wikipedia gives a density of 12.364 g/cm3 at 20 °C and a melting point of 2334 °C, and it is not attacked by acids, even aqua regia. It is recovered as a by-product of nickel, copper and platinum processing, and the USGS lists it as a critical mineral. Most use is in electronics, where a 2020 first-principles study finds that fcc ruthenium lines have lower resistance than copper below 21 nm line width. No flight or space test data were found for the metal.\n",
  "best_for": "Hard, dense electrical contacts and thin conducting layers where a very high melting point and acid resistance matter (Wikipedia, USGS)",
  "weakest_at": "Oxidation at high temperature: the source shows volatile RuO4 escaping from a thin film annealed at 600 °C in dry oxygen, and the metal is attacked by hypochlorite and halogens (Wikipedia)",
  "identity": {
    "formula": "Ru (element, atomic number 44); refined sponge and powder under ASTM B717, grades 99.80 and 99.90",
    "cas": "7440-18-8",
    "designations": [
      {
        "system": "ASTM",
        "code": "B717",
        "note": "Standard Specification for Refined Ruthenium, sponge and powder, grades 99.80 and 99.90",
        "source": "astm-b717",
        "where": "Title and scope sentence on the ASTM B717-23 listing page"
      }
    ],
    "source": "wikipedia-ru",
    "where": "Infobox, CAS number row"
  },
  "tags": {
    "environments": [],
    "stresses": [],
    "applications": [
      "electronics-and-chips"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density, ruthenium at 20 °C (Wikipedia infobox)",
      "value": 12.364,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C"
      },
      "method": "Value printed in the infobox of the Wikipedia article on ruthenium",
      "status": "ground",
      "source": "wikipedia-ru",
      "where": "Infobox, Density (at 20 °C) row",
      "source_detail": {
        "title": "Ruthenium (Wikipedia, English)",
        "url": "https://en.wikipedia.org/wiki/Ruthenium",
        "year": 2026,
        "kind": "web",
        "license": "CC BY-SA 4.0 (cited, not reproduced)"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, solid ruthenium (WebElements)",
      "value": 12370,
      "bound": "exact",
      "unit": "kg/m3",
      "scope": "material",
      "conditions": {
        "temperature": "not stated"
      },
      "method": "Value printed on the WebElements physical-properties page",
      "status": "ground",
      "source": "webelements-ru",
      "where": "Physical properties page, row Density of solid",
      "source_detail": {
        "title": "WebElements, Ruthenium physical properties",
        "url": "https://webelements.co.uk/ruthenium/physics.html",
        "kind": "database",
        "license": "WebElements, University of Sheffield (cited, not reproduced)"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, ruthenium at 20 °C (Goodfellow)",
      "value": 12.2,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C",
        "purity": "99.9% (3N)"
      },
      "method": "Value printed in a supplier product table for ruthenium rod",
      "status": "ground",
      "note": "Goodfellow is a supplier catalogue, not a manufacturer datasheet. The three density values differ by about 1 percent and are all recorded.",
      "source": "goodfellow-ru",
      "where": "Physical Properties table, Density row",
      "source_detail": {
        "title": "Goodfellow, Ruthenium rod (99.9% 3N), product group",
        "url": "https://www.goodfellow.com/usa/ruthenium-rod-group",
        "kind": "datasheet",
        "license": "supplier catalogue (cited, not reproduced)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point, ruthenium (Wikipedia infobox)",
      "value": 2334,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "unit_in_source": "2607 K (2334 °C, 4233 °F)",
        "pressure": "not stated"
      },
      "method": "Value printed in the infobox of the Wikipedia article on ruthenium",
      "status": "ground",
      "source": "wikipedia-ru",
      "where": "Infobox, Melting point row",
      "source_detail": {
        "title": "Ruthenium (Wikipedia, English)",
        "url": "https://en.wikipedia.org/wiki/Ruthenium",
        "year": 2026,
        "kind": "web",
        "license": "CC BY-SA 4.0 (cited, not reproduced)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point, ruthenium (PubChem experimental property)",
      "value": 2334,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "form": "element, CAS 7440-18-8",
        "pressure": "not stated"
      },
      "method": "Experimental value listed in the PubChem record for the element",
      "status": "ground",
      "note": "PubChem also lists 2333 °C under a second experimental entry; that value is not entered.",
      "source": "pubchem-ru",
      "where": "Chemical and Physical Properties, Experimental Properties, Melting Point (2,334 °C)",
      "source_detail": {
        "title": "PubChem compound record, ruthenium element (CID 23950)",
        "id": "CID 23950; CAS 7440-18-8",
        "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23950/JSON",
        "kind": "database",
        "license": "public domain (NCBI)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting point, ruthenium (Goodfellow)",
      "value": 2310,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "purity": "99.9% (3N)"
      },
      "method": "Value printed in a supplier product table for ruthenium rod",
      "status": "ground",
      "note": "The Goodfellow value is 24 °C below the Wikipedia and PubChem values; both are recorded.",
      "source": "goodfellow-ru",
      "where": "Thermal Properties table, Melting point row",
      "source_detail": {
        "title": "Goodfellow, Ruthenium rod (99.9% 3N), product group",
        "url": "https://www.goodfellow.com/usa/ruthenium-rod-group",
        "kind": "datasheet",
        "license": "supplier catalogue (cited, not reproduced)"
      }
    },
    {
      "benchmark": "boiling_point",
      "label": "Boiling point, ruthenium (Wikipedia infobox)",
      "value": 4150,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "unit_in_source": "4423 K (4150 °C, 7502 °F)",
        "pressure": "not stated"
      },
      "method": "Value printed in the infobox of the Wikipedia article on ruthenium",
      "status": "ground",
      "source": "wikipedia-ru",
      "where": "Infobox, Boiling point row",
      "source_detail": {
        "title": "Ruthenium (Wikipedia, English)",
        "url": "https://en.wikipedia.org/wiki/Ruthenium",
        "year": 2026,
        "kind": "web",
        "license": "CC BY-SA 4.0 (cited, not reproduced)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, ruthenium (Wikipedia infobox)",
      "value": 117,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "temperature": "not stated"
      },
      "method": "Value printed in the infobox of the Wikipedia article on ruthenium",
      "status": "ground",
      "source": "wikipedia-ru",
      "where": "Infobox, Thermal conductivity row",
      "source_detail": {
        "title": "Ruthenium (Wikipedia, English)",
        "url": "https://en.wikipedia.org/wiki/Ruthenium",
        "year": 2026,
        "kind": "web",
        "license": "CC BY-SA 4.0 (cited, not reproduced)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, ruthenium (WebElements)",
      "value": 120,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "temperature": "not stated"
      },
      "method": "Value printed on the WebElements physical-properties page",
      "status": "ground",
      "note": "WebElements gives 120 and Wikipedia and Goodfellow give 117; the difference is recorded, not resolved.",
      "source": "webelements-ru",
      "where": "Physical properties page, row Thermal conductivity",
      "source_detail": {
        "title": "WebElements, Ruthenium physical properties",
        "url": "https://webelements.co.uk/ruthenium/physics.html",
        "kind": "database",
        "license": "WebElements, University of Sheffield (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity, ruthenium at 0 °C (Wikipedia infobox)",
      "value": 71,
      "bound": "exact",
      "unit": "nΩ·m",
      "scope": "material",
      "conditions": {
        "temperature": "0 °C",
        "unit_in_source": "71 nΩ⋅m (at 0 °C)"
      },
      "method": "Value printed in the infobox of the Wikipedia article on ruthenium",
      "status": "ground",
      "source": "wikipedia-ru",
      "where": "Infobox, Electrical resistivity row",
      "source_detail": {
        "title": "Ruthenium (Wikipedia, English)",
        "url": "https://en.wikipedia.org/wiki/Ruthenium",
        "year": 2026,
        "kind": "web",
        "license": "CC BY-SA 4.0 (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity, ruthenium at 20 °C (Goodfellow)",
      "value": 7.7,
      "bound": "exact",
      "unit": "µΩ·cm",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C",
        "purity": "99.9% (3N)"
      },
      "method": "Value printed in a supplier product table for ruthenium rod",
      "status": "ground",
      "note": "The same 7.7 µΩ·cm is 7.7e-8 Ω·m; WebElements gives 7.1e-8 Ω·m without a temperature, and both are recorded.",
      "source": "goodfellow-ru",
      "where": "Electrical Properties table, Electrical resistivity row",
      "source_detail": {
        "title": "Goodfellow, Ruthenium rod (99.9% 3N), product group",
        "url": "https://www.goodfellow.com/usa/ruthenium-rod-group",
        "kind": "datasheet",
        "license": "supplier catalogue (cited, not reproduced)"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity, fcc ruthenium bulk (ab initio, phonon-limited)",
      "value": 3.8,
      "bound": "exact",
      "unit": "µΩ·cm",
      "scope": "material",
      "conditions": {
        "phase": "fcc",
        "basis": "phonon-limited bulk resistivity from first-principles calculation"
      },
      "method": "Calculated in the cited arXiv paper, not measured",
      "status": "calculated",
      "note": "The same paper gives 11.1 µΩ·cm for hcp ruthenium in the same table and an experimental reference of 7.8 µΩ·cm for hcp ruthenium; the calculated fcc value is entered only.",
      "source": "arxiv-ru-interconnect",
      "where": "Table I, row Ru (fcc), column rho",
      "source_detail": {
        "title": "First principles evaluation of fcc ruthenium for use in advanced interconnects (Philip et al., IBM Research and Synopsys)",
        "id": "arXiv 2001.02216",
        "url": "https://arxiv.org/pdf/2001.02216",
        "year": 2020,
        "kind": "paper",
        "license": "arXiv preprint (cited, not reproduced)"
      }
    },
    {
      "benchmark": "cte",
      "label": "Coefficient of thermal expansion at 20 °C",
      "value": 6.78,
      "bound": "exact",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "temperature": "20 °C",
        "unit_in_source": "6.78×10−6/K (at 20 °C)"
      },
      "method": "Value printed in the infobox of the Wikipedia article on ruthenium",
      "status": "ground",
      "source": "wikipedia-ru",
      "where": "Infobox, Thermal expansion row",
      "source_detail": {
        "title": "Ruthenium (Wikipedia, English)",
        "url": "https://en.wikipedia.org/wiki/Ruthenium",
        "year": 2026,
        "kind": "web",
        "license": "CC BY-SA 4.0 (cited, not reproduced)"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Young's modulus, ruthenium (Wikipedia infobox)",
      "value": 447,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "temperature": "not stated"
      },
      "method": "Value printed in the infobox of the Wikipedia article on ruthenium",
      "status": "ground",
      "source": "wikipedia-ru",
      "where": "Infobox, Young's modulus row",
      "source_detail": {
        "title": "Ruthenium (Wikipedia, English)",
        "url": "https://en.wikipedia.org/wiki/Ruthenium",
        "year": 2026,
        "kind": "web",
        "license": "CC BY-SA 4.0 (cited, not reproduced)"
      }
    },
    {
      "benchmark": "shear_modulus",
      "label": "Shear modulus, ruthenium (Wikipedia infobox)",
      "value": 173,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "temperature": "not stated"
      },
      "method": "Value printed in the infobox of the Wikipedia article on ruthenium",
      "status": "ground",
      "source": "wikipedia-ru",
      "where": "Infobox, Shear modulus row",
      "source_detail": {
        "title": "Ruthenium (Wikipedia, English)",
        "url": "https://en.wikipedia.org/wiki/Ruthenium",
        "year": 2026,
        "kind": "web",
        "license": "CC BY-SA 4.0 (cited, not reproduced)"
      }
    },
    {
      "benchmark": "bulk_modulus",
      "label": "Bulk modulus, ruthenium (Wikipedia infobox)",
      "value": 220,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "temperature": "not stated"
      },
      "method": "Value printed in the infobox of the Wikipedia article on ruthenium",
      "status": "ground",
      "note": "Goodfellow gives 286 GPa for the same property; the two values differ and both are recorded.",
      "source": "wikipedia-ru",
      "where": "Infobox, Bulk modulus row",
      "source_detail": {
        "title": "Ruthenium (Wikipedia, English)",
        "url": "https://en.wikipedia.org/wiki/Ruthenium",
        "year": 2026,
        "kind": "web",
        "license": "CC BY-SA 4.0 (cited, not reproduced)"
      }
    },
    {
      "benchmark": "bulk_modulus",
      "label": "Bulk modulus, ruthenium (Goodfellow)",
      "value": 286,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "purity": "99.9% (3N)"
      },
      "method": "Value printed in a supplier product table for ruthenium rod",
      "status": "ground",
      "source": "goodfellow-ru",
      "where": "Mechanical Properties table, Bulk modulus row",
      "source_detail": {
        "title": "Goodfellow, Ruthenium rod (99.9% 3N), product group",
        "url": "https://www.goodfellow.com/usa/ruthenium-rod-group",
        "kind": "datasheet",
        "license": "supplier catalogue (cited, not reproduced)"
      }
    },
    {
      "benchmark": "poissons_ratio",
      "label": "Poisson's ratio, ruthenium",
      "value": 0.3,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "temperature": "not stated"
      },
      "method": "Value printed in the infobox of the Wikipedia article on ruthenium, with no unit or condition",
      "status": "ground",
      "source": "wikipedia-ru",
      "where": "Infobox, Poisson ratio row",
      "source_detail": {
        "title": "Ruthenium (Wikipedia, English)",
        "url": "https://en.wikipedia.org/wiki/Ruthenium",
        "year": 2026,
        "kind": "web",
        "license": "CC BY-SA 4.0 (cited, not reproduced)"
      }
    },
    {
      "benchmark": "mohs_hardness",
      "label": "Mohs hardness, ruthenium",
      "value": 6.5,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "temperature": "not stated"
      },
      "method": "Value printed in the infobox of the Wikipedia article on ruthenium, with no unit",
      "status": "ground",
      "note": "mohs_hardness is not in the canonical property list.",
      "source": "wikipedia-ru",
      "where": "Infobox, Mohs hardness row",
      "source_detail": {
        "title": "Ruthenium (Wikipedia, English)",
        "url": "https://en.wikipedia.org/wiki/Ruthenium",
        "year": 2026,
        "kind": "web",
        "license": "CC BY-SA 4.0 (cited, not reproduced)"
      }
    },
    {
      "benchmark": "brinell_hardness",
      "label": "Brinell hardness, ruthenium (Wikipedia infobox)",
      "value": 2160,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "temper": "not stated"
      },
      "method": "Value printed in the infobox of the Wikipedia article on ruthenium",
      "status": "ground",
      "note": "brinell_hardness is not in the canonical property list.",
      "source": "wikipedia-ru",
      "where": "Infobox, Brinell hardness row",
      "source_detail": {
        "title": "Ruthenium (Wikipedia, English)",
        "url": "https://en.wikipedia.org/wiki/Ruthenium",
        "year": 2026,
        "kind": "web",
        "license": "CC BY-SA 4.0 (cited, not reproduced)"
      }
    },
    {
      "benchmark": "vickers_hardness",
      "label": "Vickers hardness, ruthenium hard temper (Goodfellow)",
      "value": 750,
      "bound": "exact",
      "unit": "kgf/mm2",
      "scope": "material",
      "conditions": {
        "temper": "hard",
        "purity": "99.9% (3N)"
      },
      "method": "Value printed in a supplier product table for ruthenium rod",
      "status": "ground",
      "note": "vickers_hardness is not in the canonical property list.",
      "source": "goodfellow-ru",
      "where": "Mechanical Properties table, Vickers hardness row, column Hard",
      "source_detail": {
        "title": "Goodfellow, Ruthenium rod (99.9% 3N), product group",
        "url": "https://www.goodfellow.com/usa/ruthenium-rod-group",
        "kind": "datasheet",
        "license": "supplier catalogue (cited, not reproduced)"
      }
    },
    {
      "benchmark": "vickers_hardness",
      "label": "Vickers hardness, ruthenium soft temper (Goodfellow)",
      "value": 350,
      "bound": "exact",
      "unit": "kgf/mm2",
      "scope": "material",
      "conditions": {
        "temper": "soft",
        "purity": "99.9% (3N)"
      },
      "method": "Value printed in a supplier product table for ruthenium rod",
      "status": "ground",
      "note": "vickers_hardness is not in the canonical property list.",
      "source": "goodfellow-ru",
      "where": "Mechanical Properties table, Vickers hardness row, column Soft",
      "source_detail": {
        "title": "Goodfellow, Ruthenium rod (99.9% 3N), product group",
        "url": "https://www.goodfellow.com/usa/ruthenium-rod-group",
        "kind": "datasheet",
        "license": "supplier catalogue (cited, not reproduced)"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Acids, including aqua regia",
      "headline": "Ruthenium is not attacked by acids, even aqua regia, according to the Wikipedia summary.",
      "effect": "The Wikipedia chemical-properties section gives this as the metal's acid resistance. No rate or concentration is stated.",
      "rating": "low",
      "conditions": {
        "basis": "encyclopaedia summary; concentrations not stated"
      },
      "source": "wikipedia-ru",
      "where": "Chemical properties section"
    },
    {
      "environment": "Sodium hypochlorite and halogens at high temperature",
      "headline": "Ruthenium is attacked by sodium hypochlorite and by halogens at high temperatures.",
      "effect": "The Wikipedia summary names these attacks. It gives no temperature, rate or product for either.",
      "rating": "moderate",
      "conditions": {
        "temperature": "high, not stated",
        "basis": "encyclopaedia summary; no measured rate"
      },
      "source": "wikipedia-ru",
      "where": "Chemical properties section"
    },
    {
      "environment": "Dry oxygen at 600 °C (amorphous Ru-Si-O thin film)",
      "headline": "In a thin Ru-Si-O film annealed in dry oxygen at 600 °C, RuO2 grains grew out of the film and volatile RuO4 escaped.",
      "effect": "The paper studies a silicate thin film, not bulk ruthenium metal, so it shows oxide growth and RuO4 loss in that film only.",
      "rating": "moderate",
      "conditions": {
        "temperature": "600 °C",
        "atmosphere": "dry oxygen, 30 min anneal",
        "specimen": "amorphous Ru-Si-O thin film"
      },
      "source": "caltech-ru-sio",
      "where": "Abstract"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem reports ECHA C&L notifications for ruthenium: H228 flammable solid (49.9 %) and H413 may cause long lasting harmful effects to aquatic life (22.9 %). The signal word is Danger.",
        "ghs": [
          "H228",
          "H413"
        ],
        "source": "pubchem-ru",
        "where": "Safety and Hazards, GHS Classification"
      },
      {
        "text": "The Chemicalbook safety data sheet for ruthenium (revision 2026-06-27) gives the signal word Danger and the codes H228 flammable solid, H252 self-heating in large quantities, H315 causes skin irritation, H319 causes serious eye irritation and H335 may cause respiratory irritation.",
        "ghs": [
          "H228",
          "H252",
          "H315",
          "H319",
          "H335"
        ],
        "source": "chemicalbook-ru-sds",
        "where": "Section 2, Hazard statements"
      }
    ],
    "failure_risks": [
      {
        "mode": "Flammable solid",
        "trigger": "Ruthenium metal handled as sponge or powder in air",
        "consequence": "The SDS classifies the material as a flammable solid (H228), and PubChem's notifications carry the same code.",
        "severity": "moderate",
        "source": "chemicalbook-ru-sds",
        "where": "Section 2, Hazard statements H228"
      },
      {
        "mode": "Self-heating",
        "trigger": "Large quantities of the material",
        "consequence": "The SDS lists H252 self-heating in large quantities; may catch fire.",
        "severity": "moderate",
        "source": "chemicalbook-ru-sds",
        "where": "Section 2, Hazard statements H252"
      }
    ],
    "side_effects": [
      {
        "text": "Ruthenium price averaged 451.02 dollars per troy ounce in 2024 and an estimated 690 dollars in 2025, according to the USGS price table.",
        "affects": "Cost of electronic contacts, resistors and research samples",
        "source": "usgs-pgm-2026",
        "where": "Salient Statistics, Price, dollars per troy ounce, Ruthenium row"
      }
    ],
    "handling": [
      {
        "text": "The SDS lists the material as combustible in Section 5 and as a flammable solid in Section 2.",
        "source": "chemicalbook-ru-sds",
        "where": "Sections 2 and 5"
      },
      {
        "text": "The SDS gives no fire-protection or storage instructions beyond its GHS classification.",
        "source": "chemicalbook-ru-sds",
        "where": "Sections 2 to 9"
      }
    ],
    "mitigations": []
  },
  "uses": [
    {
      "application": "electronics-and-chips",
      "device": "Ruthenium liner or conductor in advanced chip interconnects (calculation only)",
      "example": "A first-principles study finds that the line resistance of fcc ruthenium is lower than that of copper below 21 nm line width, because copper loses conductor volume to adhesion and wetting liners.",
      "source": "arxiv-ru-interconnect",
      "where": "Abstract, last sentences"
    },
    {
      "application": "electronics-and-chips",
      "device": "Electrical contacts and chip resistors in computers",
      "example": "The USGS 2025 critical-minerals entry for ruthenium says it is used as catalysts, as well as electrical contacts and chip resistors in computers.",
      "source": "usgs-crit-2025",
      "where": "List entry for Ruthenium"
    }
  ],
  "supply": [
    {
      "subject": "Abundance in the Earth's crust",
      "abundance": "about 100 parts per trillion (Wikipedia, Occurrence section)",
      "producers": [],
      "critical_lists": [],
      "substitutes": [],
      "source": "wikipedia-ru",
      "where": "Occurrence section"
    },
    {
      "subject": "Ruthenium mine output",
      "producers": [],
      "critical_lists": [],
      "substitutes": [],
      "source": "usgs-pgm-2026",
      "where": "Salient Statistics and World Mine Production and Reserves table"
    },
    {
      "subject": "United States ruthenium imports for consumption",
      "producers": [],
      "critical_lists": [],
      "substitutes": [],
      "source": "usgs-pgm-2026",
      "where": "Salient Statistics, Imports for consumption, Ruthenium row"
    },
    {
      "subject": "Ruthenium recovery",
      "producers": [],
      "critical_lists": [],
      "recycling": "Ruthenium is recovered as a by-product of processing nickel, copper and platinum ores, collecting in the anode mud from electrorefining. No ruthenium recovery figure is given in the USGS summary.",
      "substitutes": [],
      "source": "wikipedia-ru",
      "where": "Production section"
    },
    {
      "subject": "Critical-mineral status",
      "producers": [],
      "critical_lists": [
        {
          "list": "USGS 2025 List of Critical Minerals",
          "listed": true
        }
      ],
      "substitutes": [],
      "source": "usgs-crit-2025",
      "where": "List entry for Ruthenium"
    },
    {
      "subject": "Substitution",
      "producers": [],
      "critical_lists": [],
      "substitutes": [
        "USGS: for some industrial end uses one platinum-group metal can substitute for another, but with losses in efficiency."
      ],
      "source": "usgs-pgm-2026",
      "where": "Substitutes paragraph"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Wikipedia: Ruthenium",
      "type": "database",
      "url": "https://en.wikipedia.org/wiki/Ruthenium",
      "year": 2026
    },
    {
      "title": "Goodfellow: Ruthenium rod, 99.9% (3N), product group page",
      "type": "datasheet",
      "url": "https://www.goodfellow.com/usa/ruthenium-rod-group"
    },
    {
      "title": "WebElements: Ruthenium physical properties",
      "type": "database",
      "url": "https://webelements.co.uk/ruthenium/physics.html"
    },
    {
      "title": "PubChem compound record for the ruthenium element",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/23950"
    },
    {
      "title": "Chemicalbook safety data sheet: ruthenium, revision 2026-06-27",
      "type": "sds",
      "url": "https://www.chemicalbook.com/msds/ruthenium.htm",
      "year": 2026
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Platinum-Group Metals",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-platinum-group.pdf",
      "year": 2026
    },
    {
      "title": "USGS 2025 List of Critical Minerals (final list, 60 minerals)",
      "type": "report",
      "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals",
      "year": 2025
    },
    {
      "title": "ASTM B717-23 Standard Specification for Refined Ruthenium (listing page)",
      "type": "standard",
      "url": "https://eshop.normservis.sk/norma/astm-b717-23-1.4.2023.html",
      "year": 2023
    },
    {
      "title": "Philip et al., First principles evaluation of fcc ruthenium for use in advanced interconnects (arXiv 2001.02216)",
      "type": "paper",
      "url": "https://arxiv.org/pdf/2001.02216",
      "year": 2020
    },
    {
      "title": "Instability of Amorphous Ru-Si-O Thin Films under Thermal Oxidation, J. Electrochem. Soc. 146(4), 1546-1548",
      "type": "paper",
      "url": "https://authors.library.caltech.edu/records/xm8cb-psc97",
      "year": 1999
    }
  ],
  "gaps": [
    "No ruthenium mine output or country shares were found. The USGS 2026 platinum-group summary gives mine production only for palladium and platinum, so the producers list is empty.",
    "No UNS, EN, DIN, JIS or trade-name designation was found for ruthenium. A UNS search returned none, and the ASTM B717 page prints none. ASTM B717 is the only designation entered.",
    "Melting point differs across sources: Wikipedia and PubChem give 2334 °C, Goodfellow gives 2310 °C. Both are recorded.",
    "Thermal conductivity differs: Wikipedia and Goodfellow give 117 W/(m·K), WebElements gives 120 W/(m·K) without a temperature. Both are recorded.",
    "Bulk modulus differs: Wikipedia gives 220 GPa and Goodfellow gives 286 GPa. Both are recorded.",
    "The ChemicalBook SDS gives a relative density of 12,45 g/mL with no temperature. It is a secondary listing and was not entered.",
    "The PubChem density (12.1 at 25 °C) is printed without a unit, so it was not entered.",
    "The ChemicalBook SDS and PubChem give different GHS codes (H252, H315, H319 and H335 in the SDS; H413 in PubChem). Both are recorded and the difference is not resolved.",
    "No manufacturer datasheet for ruthenium (Heraeus, Johnson Matthey) was found in search. Goodfellow is a supplier catalogue, and the hardness values come only from it.",
    "No space flight, vacuum, radiation or atomic-oxygen test data were found. A NASA search returned only iridium-coated rhenium thruster chambers, not ruthenium, so no environment tag is set.",
    "Ruthenium-based dye sensitizers were found in open reviews, but they are compounds, not the metal, so they are not listed as a use.",
    "The EU critical raw materials list was not checked for ruthenium.",
    "Brinell and Mohs hardness and the Vickers rows are not in the canonical property list; short snake_case names are used as noted on each row."
  ],
  "story": {
    "why": "Ruthenium is a hard, dense platinum-group metal. Wikipedia gives a density of 12.364 g/cm3 at 20 °C and a melting point of 2334 °C, and it is not attacked by acids, even aqua regia. Its electrical resistivity is 71 nΩ·m at 0 °C according to Wikipedia, and it is a minor by-product of platinum ores. Its main use is in electronics, where it is studied as a conductor and liner for advanced chip interconnects.",
    "uses": [
      {
        "where": "Electronics and chips",
        "line": "A first-principles study finds that fcc ruthenium lines have lower resistance than copper below 21 nm line width, because copper loses conductor volume to liners. This is a calculation, not a production result."
      },
      {
        "where": "Electrical contacts and chip resistors",
        "line": "The USGS 2025 critical-minerals list says ruthenium is used as catalysts, as well as electrical contacts and chip resistors in computers."
      }
    ],
    "can_do": [
      {
        "label": "Stay solid at high heat",
        "line": "Wikipedia and PubChem give 2334 °C. Goodfellow gives 2310 °C.",
        "benchmark": "melting_point",
        "scope": "material",
        "value": "2334 °C melting point"
      },
      {
        "label": "Dense and hard",
        "line": "Wikipedia gives 12.364 g/cm3 at 20 °C. Goodfellow gives a Vickers hardness of 750 kgf/mm2 in the hard temper and 350 kgf/mm2 in the soft temper.",
        "benchmark": "density",
        "scope": "material",
        "value": "12.364 g/cm3 density"
      },
      {
        "label": "Conduct current",
        "line": "Wikipedia gives 71 nΩ·m at 0 °C. Goodfellow gives 7.7 µΩ·cm at 20 °C.",
        "benchmark": "electrical_resistivity",
        "scope": "material",
        "value": "71 nΩ·m resistivity"
      },
      {
        "label": "Resist acid",
        "line": "Wikipedia says the metal is not attacked by acids, even aqua regia, but is attacked by hypochlorite and halogens at high temperature.",
        "scope": "material",
        "value": "Not attacked by acids"
      }
    ],
    "compare": "Within this profile, the cited calculation puts fcc ruthenium at 3.8 µΩ·cm and hcp ruthenium at 11.1 µΩ·cm, in the same table. The measured resistivity values (71 nΩ·m at 0 °C in Wikipedia, 7.7 µΩ·cm at 20 °C in Goodfellow) are not directly comparable with the calculated ones. The thermal conductivity values disagree between sources, and the sources do not compare ruthenium with other platinum-group metals.",
    "compare_rows": [
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Melting point",
        "benchmark": "melting_point",
        "scope": "material"
      },
      {
        "label": "Thermal conductivity",
        "benchmark": "thermal_conductivity",
        "scope": "material"
      }
    ],
    "handling": [
      "Treat the sponge and powder as a flammable solid (H228) and keep it away from ignition sources.",
      "Expect self-heating in large quantities (H252), as the SDS warns.",
      "The SDS lists serious eye irritation (H319) and skin irritation (H315)."
    ],
    "good_for": [
      "Electrical contacts and thin conducting layers in electronics, as the USGS and the arXiv study describe.",
      "Acid-resistant parts, since the metal is not attacked by acids, even aqua regia, according to Wikipedia."
    ],
    "watch_out": [
      "Oxidation at high temperature: volatile RuO4 escaped from a thin film annealed at 600 °C in dry oxygen.",
      "Flammable solid and self-heating in large quantities, according to the SDS.",
      "Thermal conductivity and bulk modulus differ between sources, and these differences are not resolved.",
      "No ruthenium mine output or country shares were found, so supply concentration is not known from these sources."
    ],
    "verdict": "Ruthenium is a hard, dense platinum-group metal that resists acids and has a very high melting point. Its main use is in electronics, where it is studied for chip interconnects and used in contacts and resistors. The SDS classes it as a flammable solid, and the sources do not give supply shares or any space test data.",
    "recipe": {
      "line": "Ruthenium is a single-element metal (Ru, atomic number 44) with a hexagonal close-packed crystal structure (Wikipedia infobox). It is refined from platinum-group ore: the metals are dissolved, ruthenium is separated from osmium as volatile oxides, and ammonium ruthenium chloride is reduced with hydrogen to a powder (Wikipedia, Production).",
      "parts": [
        {
          "name": "Ruthenium",
          "symbol": "Ru",
          "role": "The whole material. Wikipedia gives a standard atomic weight of 101.07 and lists it as a rare transition metal, usually a minor component of platinum ores.",
          "atoms": 1,
          "atomic_weight": 101.07
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The SDS and PubChem both list ruthenium as a flammable solid, and the SDS adds irritation codes. Little health data are given in the sources.",
        "points": [
          {
            "label": "The metal",
            "line": "The SDS lists H228 flammable solid, H252 self-heating in large quantities, H315 skin irritation, H319 serious eye irritation and H335 respiratory irritation, with the signal word Danger. PubChem notifications list H228 and H413."
          },
          {
            "label": "Environment",
            "line": "PubChem notifications give H413, which may cause long lasting harmful effects to aquatic life."
          }
        ],
        "level": 1,
        "verdict": "Flammable solid in the SDS"
      },
      {
        "title": "If it fails",
        "lead": "These routes come from the SDS and from the high-temperature sources. None are from field incidents.",
        "points": [
          {
            "label": "Oxidation",
            "line": "In a thin Ru-Si-O film annealed in dry oxygen at 600 °C, RuO2 grew and volatile RuO4 escaped. This is a film result, not bulk metal."
          },
          {
            "label": "Self-heating",
            "line": "The SDS lists self-heating in large quantities, which may catch fire."
          }
        ]
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Fire",
            "line": "The SDS classes the metal as combustible in Section 5 and as a flammable solid in Section 2."
          },
          {
            "label": "Storage",
            "line": "The SDS gives no storage instructions beyond its GHS classification."
          }
        ]
      }
    ]
  },
  "updated": "2026-10-26",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 22,
    "unreachable": 0,
    "caveats": 4,
    "note": "Values were read by an AI assistant on 2026-10-26 from the pages named in each entry. The arXiv paper was read from a PDF download. Caveats: the melting point, thermal conductivity and bulk modulus sources disagree; the fcc resistivity is a calculation; the SDS and PubChem hazard codes differ."
  },
  "sources": {
    "wikipedia-ru": {
      "title": "Ruthenium (Wikipedia, English)",
      "url": "https://en.wikipedia.org/wiki/Ruthenium",
      "year": 2026,
      "kind": "web",
      "license": "CC BY-SA 4.0 (cited, not reproduced)"
    },
    "usgs-pgm-2026": {
      "title": "Mineral Commodity Summaries 2026, Platinum-Group Metals",
      "id": "USGS MCS 2026, February 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-platinum-group.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-crit-2025": {
      "title": "About the 2025 List of Critical Minerals (USGS, final list of 60 minerals)",
      "id": "Final 2025 List of Critical Minerals, November 2025",
      "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals",
      "year": 2025,
      "kind": "web",
      "license": "public domain (USGS)"
    },
    "webelements-ru": {
      "title": "WebElements, Ruthenium physical properties",
      "url": "https://webelements.co.uk/ruthenium/physics.html",
      "kind": "database",
      "license": "WebElements, University of Sheffield (cited, not reproduced)"
    },
    "goodfellow-ru": {
      "title": "Goodfellow, Ruthenium rod (99.9% 3N), product group",
      "url": "https://www.goodfellow.com/usa/ruthenium-rod-group",
      "kind": "datasheet",
      "license": "supplier catalogue (cited, not reproduced)"
    },
    "pubchem-ru": {
      "title": "PubChem compound record, ruthenium element (CID 23950)",
      "id": "CID 23950; CAS 7440-18-8",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23950/JSON",
      "kind": "database",
      "license": "public domain (NCBI)"
    },
    "chemicalbook-ru-sds": {
      "title": "Chemicalbook safety data sheet, ruthenium (revision 2026-06-27)",
      "url": "https://www.chemicalbook.com/msds/ruthenium.htm",
      "year": 2026,
      "kind": "datasheet",
      "license": "supplier listing (cited, not reproduced)"
    },
    "arxiv-ru-interconnect": {
      "title": "First principles evaluation of fcc ruthenium for use in advanced interconnects (Philip et al., IBM Research and Synopsys)",
      "id": "arXiv 2001.02216",
      "url": "https://arxiv.org/pdf/2001.02216",
      "year": 2020,
      "kind": "paper",
      "license": "arXiv preprint (cited, not reproduced)"
    },
    "caltech-ru-sio": {
      "title": "Instability of Amorphous Ru-Si-O Thin Films under Thermal Oxidation (J. Electrochem. Soc. 146(4), 1546-1548)",
      "url": "https://authors.library.caltech.edu/records/xm8cb-psc97",
      "year": 1999,
      "kind": "paper",
      "license": "Caltech authors record (cited, not reproduced)"
    },
    "astm-b717": {
      "title": "ASTM B717-23 Standard Specification for Refined Ruthenium (listing page)",
      "url": "https://eshop.normservis.sk/norma/astm-b717-23-1.4.2023.html",
      "year": 2023,
      "kind": "standard",
      "license": "standard listing (cited, not reproduced)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/ruthenium/"
}