spore: profile
id: cobalt
spore_version: 0.2
family: cobalt-alloys
name: Cobalt
abbreviation: Co
role: magnet, superalloy and battery metal
category: metals
type: heavy-metals
summary: |
  Cobalt is the element Co (atomic number 27), a hard, ferromagnetic transition metal. The unalloyed metal has a density of 8.90 g/cm3 at 20 °C, a melting point of 1495 °C and a Curie temperature of 1115 °C. Goodfellow gives its thermal conductivity as 100 W/(m·K). Most cobalt is used as an alloy element or in compounds: lithium-ion cathodes, cobalt-base superalloys for aircraft gas turbines, and samarium-cobalt magnets. Congo (Kinshasa) mined an estimated 73 % of world cobalt in 2025, and the USGS reports export quotas that replaced a temporary export ban.
best_for: 'Hot magnetic and load-bearing alloys: a Curie temperature of 1115 °C and a melting point of 1495 °C in the pure metal, with cobalt-base superalloys for aircraft gas turbines'
weakest_at: 'Supply and fine powder: Congo (Kinshasa) mined an estimated 73 % of world cobalt in 2025, and finely divided cobalt can ignite in air'
identity:
  formula: Co (element, atomic number 27); unalloyed cobalt metal, hexagonal close-packed (alpha-Co) below 417 °C and face-centred cubic (beta-Co) above
  cas: 7440-48-4
  source: goodfellow-co-metal
  where: CAS Number row and Atomic Number row (27) of the Goodfellow high-purity cobalt material page; Crystal Structure row gives hcp below 417 °C and fcc above
tags:
  environments: []
  stresses:
    - extreme-heat
  applications:
    - batteries
    - electronics-and-chips
    - mechanisms
    - propulsion-and-tanks
properties:
  - benchmark: density
    label: Density at 20 °C, high-purity cobalt metal
    value: 8.9
    unit: g/cm3
    scope: material
    conditions:
      temperature: 20 °C
      form: high-purity cobalt metal (Goodfellow material page)
    method: Value printed in a supplier material data table
    status: ground
    source: goodfellow-co-metal
    where: Physical data table, row Density (20 °C)
  - benchmark: density
    label: Density at 20 °C, high-purity cobalt rod
    value: 8.9
    unit: g/cm3
    scope: material
    conditions:
      temperature: 20 °C
      form: solid rod, high-purity (Goodfellow rod page)
    method: Value printed in a supplier physical properties table
    status: ground
    source: goodfellow-co-rod
    where: Physical Properties table, row Density, 8.9@20°C
  - benchmark: melting_point
    label: Melting point, high-purity cobalt
    value: 1495
    unit: °C
    scope: material
    conditions:
      form: high-purity cobalt metal
      unit_in_source: 1,495 °C (1,768 K)
    method: Value printed in a supplier material data table
    status: ground
    source: goodfellow-co-metal
    where: Physical data table, row Melting Point, 1,495 °C (1,768 K)
  - benchmark: boiling_point
    label: Boiling point, high-purity cobalt
    value: 2870
    unit: °C
    scope: material
    conditions:
      unit_in_source: 2,870 °C (3,143 K)
      pressure: not stated
    method: Value printed in a supplier material data table
    status: ground
    source: goodfellow-co-metal
    where: Physical data table, row Boiling Point, 2,870 °C (3,143 K)
  - benchmark: boiling_point
    label: Boiling point, elemental cobalt (HSDB entry)
    value: 2927
    unit: °C
    scope: material
    conditions:
      pressure: 760 mmHg
      form: elemental cobalt
    method: Experimental value listed in PubChem, from the Hazardous Substances Data Bank (HSDB) entry
    status: ground
    note: PubChem also lists 2870 °C from an ICSC entry, so the boiling point differs by 57 °C between sources.
    source: pubchem-co
    where: Experimental Properties, Boiling Point, HSDB entry 2,927 °C
  - benchmark: curie_temperature
    label: Curie temperature, cobalt
    value: 1115
    unit: °C
    scope: material
    conditions:
      unit_in_source: 1,115 °C (1,388 K; 2,039 °F)
    method: Value printed in an encyclopaedia article
    status: ground
    source: wikipedia-co
    where: Paragraph beginning 'Cobalt is a ferromagnetic metal with a specific gravity of 8.9'
  - benchmark: electrical_resistivity
    label: Electrical resistivity at 20 °C, high-purity cobalt metal
    value: 62.4
    unit: nΩ·m
    scope: material
    conditions:
      temperature: 20 °C
      form: high-purity cobalt metal
    method: Value printed in a supplier material data table
    status: ground
    source: goodfellow-co-metal
    where: Electrical Properties table, row Electrical Resistivity, 62.4 nΩ·m (20 °C)
  - benchmark: electrical_resistivity
    label: Electrical resistivity at 20 °C, high-purity cobalt rod
    value: 6.34
    unit: µΩ·cm
    scope: material
    conditions:
      temperature: 20 °C
      form: solid rod, high-purity
    method: Value printed in a supplier electrical properties table
    status: ground
    note: The metal page prints 62.4 nΩ·m for the same quantity, which is 6.24 µΩ·cm, 0.1 µΩ·cm below this rod value.
    source: goodfellow-co-rod
    where: Electrical Properties table, row Electrical resistivity (µOhmcm), 6.34@20°C
  - benchmark: thermal_conductivity
    label: Thermal conductivity, high-purity cobalt rod (0 to 100 °C)
    value: 100
    unit: W/(m·K)
    scope: material
    conditions:
      temperature: 0 to 100 °C
      form: solid rod, high-purity
      unit_in_source: W m-1 K-1
    method: Value printed in a supplier thermal properties table
    status: ground
    source: goodfellow-co-rod
    where: Thermal Properties table, row Thermal conductivity, 100@0-100°C
  - benchmark: thermal_conductivity
    label: Thermal conductivity, cobalt rod at 298.2 K (reseller listing)
    value: 1
    unit: W/(cm·K)
    scope: material
    conditions:
      temperature: 298.2 K
      form: cobalt rod, product listing
    method: Value printed on a reseller's product specification list
    status: ground
    source: fine-metals-co-rod
    where: Product specification list, row Thermal Conductivity, 1.0 W/cm/K @ 298.2 K
  - benchmark: specific_heat
    label: Specific heat capacity, high-purity cobalt rod at 25 °C
    value: 456
    unit: J/(kg·K)
    scope: material
    conditions:
      temperature: 25 °C
      form: solid rod, high-purity
    method: Value printed in a supplier thermal properties table
    status: ground
    source: goodfellow-co-rod
    where: Thermal Properties table, row Specific heat, 456@25°C
  - benchmark: specific_heat
    label: Specific heat capacity, cobalt at 15 to 100 °C
    value: 0.442
    unit: J/g °C
    scope: material
    conditions:
      temperature: 15 to 100 °C
      unit_in_source: J/g °C
    method: Value printed in a database record (HSDB entry)
    status: ground
    source: pubchem-co
    where: Experimental Properties, Other Experimental Properties, specific heat entry 0.442 J/g °C (15-100 °C)
  - benchmark: cte
    label: Coefficient of thermal expansion, high-purity cobalt rod (0 to 100 °C)
    value: 12.5
    unit: ppm/K
    scope: material
    conditions:
      temperature: 0 to 100 °C
      form: solid rod, high-purity
      unit_in_source: x10-6 K-1
    method: Value printed in a supplier thermal properties table
    status: ground
    source: goodfellow-co-rod
    where: Thermal Properties table, row Coefficient of thermal expansion, 12.5@0-100°C
  - benchmark: cte
    label: Coefficient of thermal expansion, cobalt at 20 °C
    value: 12.9
    unit: ppm/K
    scope: material
    conditions:
      temperature: 20 °C
      unit_in_source: 12.9 × 10−6/K
    method: Value printed in an encyclopaedia infobox
    status: ground
    source: wikipedia-co
    where: Infobox, row Thermal expansion
  - benchmark: elastic_modulus
    label: Young's modulus, high-purity cobalt metal
    value: 209
    unit: GPa
    scope: material
    conditions:
      form: high-purity cobalt metal
      temperature: not stated
    method: Value printed in a supplier material data table
    status: ground
    source: goodfellow-co-metal
    where: Mechanical properties table, row Elastic (Young's) Modulus, 209 GPa
  - benchmark: elastic_modulus
    label: Tensile modulus, cobalt foil 0.025 mm thick
    value: 211
    unit: GPa
    scope: material
    conditions:
      form: foil, 0.025 mm thick, 99.8 % purity
      temper: not stated; the hard and soft rows both print 211
    method: Value printed in a supplier mechanical properties table
    status: ground
    source: goodfellow-co-foil
    where: Mechanical Properties table, row Tensile modulus (GPa)
  - benchmark: bulk_modulus
    label: Bulk modulus, cobalt foil 0.025 mm thick
    value: 181.5
    unit: GPa
    scope: material
    conditions:
      form: foil, 0.025 mm thick, 99.8 % purity
      temper: not stated; the hard and soft rows both print 181.5
    method: Value printed in a supplier mechanical properties table
    status: ground
    source: goodfellow-co-foil
    where: Mechanical Properties table, row Bulk modulus (GPa)
  - benchmark: poissons_ratio
    label: Poisson's ratio, cobalt
    value: 0.31
    unit: '-'
    scope: material
    conditions:
      temperature: not stated
    method: Value printed in an encyclopaedia infobox
    status: ground
    source: wikipedia-co
    where: Infobox, row Poisson ratio, 0.31
  - benchmark: poissons_ratio
    label: Poisson's ratio, cobalt foil 0.025 mm thick
    value: 0.32
    unit: '-'
    scope: material
    conditions:
      form: foil, 0.025 mm thick, 99.8 % purity
      temper: not stated; the hard and soft rows both print 0.32
    method: Value printed in a supplier mechanical properties table
    status: ground
    source: goodfellow-co-foil
    where: Mechanical Properties table, row Poisson's ratio
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, cobalt foil 0.025 mm thick, hard temper
    value: 1135
    unit: MPa
    scope: material
    conditions:
      form: foil, 0.025 mm thick, 99.8 % purity
      temper: hard
    method: Value printed in a supplier mechanical properties table
    status: ground
    source: goodfellow-co-foil
    where: Mechanical Properties table, row Tensile strength (MPa), material condition Hard
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, cobalt foil 0.025 mm thick, soft temper
    value: 760
    unit: MPa
    scope: material
    conditions:
      form: foil, 0.025 mm thick, 99.8 % purity
      temper: soft
    method: Value printed in a supplier mechanical properties table
    status: ground
    source: goodfellow-co-foil
    where: Mechanical Properties table, row Tensile strength (MPa), material condition Soft
  - benchmark: vickers_hardness
    label: Vickers hardness, cobalt foil 0.025 mm thick, hard temper
    value: 320
    unit: kgf/mm2
    scope: material
    conditions:
      form: foil, 0.025 mm thick, 99.8 % purity
      temper: hard
      load: not stated
    method: Value printed in a supplier mechanical properties table
    status: ground
    source: goodfellow-co-foil
    where: Mechanical Properties table, row Hardness Vickers (kgf mm-2), material condition Hard
  - benchmark: vickers_hardness
    label: Vickers hardness, cobalt foil 0.025 mm thick, soft temper
    value: 170
    unit: kgf/mm2
    scope: material
    conditions:
      form: foil, 0.025 mm thick, 99.8 % purity
      temper: soft
      load: not stated
    method: Value printed in a supplier mechanical properties table
    status: ground
    source: goodfellow-co-foil
    where: Mechanical Properties table, row Hardness Vickers (kgf mm-2), material condition Soft
  - benchmark: saturation_magnetization
    label: Saturation magnetization, cobalt
    value: 1.42
    unit: T
    scope: material
    conditions:
      temperature: not stated
    method: Value printed on a supplier material page
    status: ground
    source: goodfellow-co-metal
    where: Magnetic Properties row, 'saturation magnetization 1.42 T'
  - benchmark: heat_of_fusion
    label: Latent heat of fusion, high-purity cobalt rod
    value: 263
    unit: J/g
    scope: material
    conditions:
      form: solid rod, high-purity
    method: Value printed in a supplier thermal properties table
    status: ground
    source: goodfellow-co-rod
    where: Thermal Properties table, row Latent heat of fusion, 263
  - benchmark: phase_transformation_temperature
    label: Transformation from hcp to fcc, cobalt
    value: 417
    unit: °C
    scope: material
    conditions:
      transition: hexagonal close-packed to face-centred cubic
    method: Value printed in a database record (HSDB entry)
    status: ground
    source: pubchem-co
    where: 'Experimental Properties, Other Experimental Properties, entry ''Transformation temperature: 417 °C'''
corrosion:
  - environment: Air at room temperature
    headline: Cobalt oxidises slowly in air and forms a thin oxide layer that is less protective than chromium oxide.
    effect: Goodfellow says cobalt oxidises slowly in air at room temperature. The mixed Co3O4 spinel layer slows further oxidation but is less protective than Cr2O3, so chromium and aluminium additions improve oxidation resistance. The rating on the page is moderate.
    rating: moderate
    conditions:
      basis: supplier statement; no oxide thickness, rate or test duration printed
      temperature: room temperature
    source: goodfellow-co-metal
    where: Corrosion Resistance row (Moderate, Co3O4 spinel layer)
  - environment: Air, as a stability statement
    headline: A database record says cobalt corrodes readily in air.
    effect: PubChem's record, from the Hazardous Substances Data Bank, gives 'Corrodes readily in air' under stability and shelf life. No test conditions or rate are printed.
    conditions:
      basis: database statement; no test conditions printed
    source: pubchem-co
    where: Experimental Properties, Stability/Shelf Life entry (HSDB)
    rating: unknown
  - environment: Dilute mineral acids (hydrochloric, sulfuric, nitric)
    headline: Cobalt dissolves in dilute hydrochloric, sulfuric and nitric acids.
    effect: Goodfellow lists cobalt as dissolving in dilute HCl, H2SO4 and HNO3, and as reacting with mineral acids to form Co2+ salts. Concentrated nitric acid passivates it, and aqua regia dissolves it rapidly.
    rating: severe
    conditions:
      basis: supplier statements; acid concentrations and temperatures for the dilute acids are not printed
    source: goodfellow-co-metal
    where: Acid Resistance row
  - environment: Alkalis and many organic acids
    headline: Cobalt resists alkalis and many organic acids at room temperature.
    effect: Goodfellow lists cobalt as resistant to alkalis, and to acetic acid and many organic acids at room temperature.
    rating: low
    conditions:
      basis: supplier statement; no concentration printed
      temperature: room temperature
    source: goodfellow-co-metal
    where: Acid Resistance row
risks:
  hazards:
    - text: The EU harmonised classification under Regulation (EC) No 1272/2008, as printed in PubChem, is H317 (may cause an allergic skin reaction), H334 (may cause allergy or asthma symptoms or breathing difficulties if inhaled), H341 (suspected of causing genetic defects) and H350 (may cause cancer). Signal word Danger. Hazard classes Carc. 1B, Muta. 2, Repr. 1B and Resp. Sens. 1.
      ghs:
        - H317
        - H334
        - H341
        - H350
      source: pubchem-co
      where: GHS Classification, Regulation (EC) No 1272/2008 entry, and Hazard Classes and Categories
    - text: PubChem's ECHA C&L summary is aggregated from 2,768 company reports. One report says cobalt does not meet GHS criteria. Notified codes are H302 (65.2 %), H317 (above 99.9 %), H319 (40.8 %) and H330 (23.4 %), with signal word Danger.
      ghs:
        - H302
        - H317
        - H319
        - H330
      source: pubchem-co
      where: GHS Classification, ECHA C&L Notifications Summary
  failure_risks:
    - mode: Pyrophoric fine powder or dust
      trigger: Finely divided cobalt, including powder reduced from its oxides, exposed to air, acetylene or oxidising agents
      consequence: PubChem (HSDB) says only certain forms of cobalt metal are pyrophoric, and very fine cobalt dust reduced in hydrogen can catch fire at room temperature in air. Dust can form explosive mixtures in air, and fused ammonium nitrate with powdered metals can react violently.
      severity: high
      source: pubchem-co
      where: Fire Potential, Physical Dangers and Stability and Reactivity entries (HSDB)
    - mode: Acid attack with hydrogen release
      trigger: Contact with mineral acids such as hydrochloric or sulfuric acid
      consequence: Cobalt reacts with mineral acids to form Co2+ salts, and the reaction generates flammable and explosive hydrogen gas (HSDB).
      severity: moderate
      source: pubchem-co
      where: Hazardous Reactivities and Incompatibilities entries (HSDB)
    - mode: Surface oxidation in air
      trigger: Long exposure to air at room temperature
      consequence: Cobalt oxidises slowly to a Co3O4 layer, which is less protective than chromium oxide. The source gives no oxide thickness or rate.
      severity: low
      source: goodfellow-co-metal
      where: Corrosion Resistance row
  side_effects:
    - text: Cobalt-59 captures neutrons in nuclear reactors to form cobalt-60, which has a half-life of 5.27 years and emits gamma rays at 1.17 and 1.33 MeV. Cobalt-60 is also a corrosion product activated in reactor coolant circuits.
      affects: Radiation dose and contamination from cobalt in reactor components and in radiotherapy sources
      source: goodfellow-co-metal
      where: Isotopes table, 60Co entry
  handling:
    - text: 'Occupational limits for cobalt metal dust and fume, as Co: OSHA permissible exposure limit 0.1 mg/m3 as an 8-hour time-weighted average, and NIOSH recommended exposure limit 0.05 mg/m3 as a 10-hour time-weighted average.'
      source: pubchem-co
      where: Safety and Hazard Properties, OSHA Standards and NIOSH Recommendations entries
    - text: The NIOSH Pocket Guide excerpt in PubChem lists cough, dyspnoea, wheezing, decreased lung function, dermatitis, respiratory hypersensitivity and asthma as symptoms of cobalt metal dust and fume. Target organs are the skin and respiratory system.
      source: pubchem-co
      where: Health Hazards, excerpt from NIOSH Pocket Guide (2024)
    - text: ATSDR lists cancer, skin, blood-forming, liver and respiratory effects as the affected organ systems for cobalt.
      source: atsdr-cobalt
      where: Affected Organ Systems line
    - text: Keep finely divided cobalt away from air, acetylene, oxidising agents and ammonium nitrate. PubChem warns of violent reactions with these.
      source: pubchem-co
      where: Reactivity Profile and Hazardous Reactivities and Incompatibilities entries (HSDB)
  mitigations: []
uses:
  - application: batteries
    device: Cathode metal in lithium-ion cells (lithium cobalt oxide and nickel-manganese-cobalt cathodes)
    example: USGS says the cobalt content of lithium-ion batteries is the leading global use of cobalt. Cobalt-free cells using iron and phosphorus held a significant market share in China.
    source: usgs-mcs2026-cobalt
    where: Substitutes paragraph
  - application: propulsion-and-tanks
    device: Cobalt-base superalloys for aircraft gas turbine engines
    example: USGS says superalloys took 51 % of cobalt consumed in the United States in 2025, mainly for aircraft gas turbine engines. Goodfellow adds nozzle guide vanes, combustion liners and first-stage turbine blades.
    source: usgs-mcs2026-cobalt
    where: Domestic Production and Use paragraph
  - application: electronics-and-chips
    device: Connectors, thermal switches and microsensors in aerospace electronics
    example: Wikipedia says cobalt alloys are used in connectors, thermal switches and microsensors that must endure extreme temperatures, vibration and radiation, conditions typical in satellites, fighter aircraft and hypersonic systems.
    source: wikipedia-co
    where: Alloys section, second paragraph on aerospace-grade electrical components
  - application: mechanisms
    device: Samarium-cobalt permanent magnets for motors, sensors and aerospace actuators
    example: Goodfellow says samarium-cobalt magnets outperform NdFeB above about 150 °C and in corrosive environments, which makes them the choice for high-temperature motors, sensors and aerospace actuators.
    source: goodfellow-co-metal
    where: Use case table, row Permanent Magnet Research (SmCo)
supply:
  - subject: Cobalt mine production, 2025
    producers:
      - country: Congo (Kinshasa)
        share_percent: 73
        year: 2025
      - country: Indonesia
        share_percent: 14
        year: 2025
    demand: 'USGS mine production in 2025, cobalt content: Congo (Kinshasa) 230,000 t; Indonesia 44,000 t; Russia 7,700 t; Madagascar 3,900 t; Australia 3,700 t; Philippines 3,700 t; Canada 3,500 t; world total 310,000 t (rounded). The printed shares are the estimated share of world total in the Events paragraph.'
    source: usgs-mcs2026-cobalt
    where: Events, Trends, and Issues paragraph (shares); World Mine Production and Reserves table, column 2025 (tonnes)
  - subject: Cobalt reserves and resources
    producers: []
    demand: 'Reserves: Congo (Kinshasa) 6,000,000 t; Australia 1,700,000 t; Russia 800,000 t; world total 12,000,000 t (rounded). Identified world terrestrial resources are about 25 million tons, mostly in copper deposits of Congo (Kinshasa) and Zambia, nickel laterites, and magmatic nickel-copper sulfides. About 5 billion tons of cobalt is contained in sea floor polymetallic nodules.'
    source: usgs-mcs2026-cobalt
    where: World Mine Production and Reserves table, Reserves column; World Resources paragraph
  - subject: Congo (Kinshasa) export controls
    producers: []
    demand: Congo (Kinshasa) temporarily banned cobalt exports in February 2025, then replaced the ban with export quotas of 18,125 t of contained cobalt for the rest of 2025 and up to 96,600 t per year in 2026 and 2027, including 9,600 t for national strategic reserves.
    source: usgs-mcs2026-cobalt
    where: Events, Trends, and Issues paragraph
  - subject: United States cobalt use, imports and recycling
    producers: []
    demand: 'Estimated US use in 2025: superalloys 51 %, chemical applications 25 %, other metallic applications 15 %, cemented carbides 9 %. Apparent consumption 9,600 t in 2025, with net import reliance of 79 % (2025e). Import shares 2021 to 2024: Norway 26 %, Finland 16 %, Canada 14 %, Japan 14 %.'
    recycling: Cobalt content of purchased scrap was 25 % of estimated cobalt consumption in 2025 (USGS).
    source: usgs-mcs2026-cobalt
    where: Domestic Production and Use; Salient Statistics; Import Sources (2021-24); Recycling paragraphs
  - subject: Cobalt price, US$ per pound
    producers: []
    demand: LME cash price averaged 23.17 in 2021, 28.83 in 2022, 15.48 in 2023, 11.84 in 2024 and 15 in 2025 (US$ per pound, USGS). The US spot cathode price averaged 21 in 2025.
    source: usgs-mcs2026-cobalt
    where: Salient Statistics, Price, average, dollars per pound
  - subject: Critical-material status
    producers: []
    critical_lists:
      - list: Described on the Goodfellow page as a critical raw material in the EU and US (list not named)
        listed: true
    source: goodfellow-co-metal
    where: Overview paragraph of the cobalt material page
  - subject: Substitutes
    producers: []
    substitutes:
      - 'USGS: cobalt-free lithium-ion cathodes using iron and phosphorus held significant market share in China. In magnets: barium or strontium ferrites, neodymium-iron-boron or nickel-iron alloys. In paints: cerium, iron, lead, manganese or vanadium. In jet engines: nickel-base alloys or ceramics. In cutting and wear-resistant materials: iron, nickel, cermets or ceramics.'
    source: usgs-mcs2026-cobalt
    where: Substitutes paragraph
documents:
  - title: Goodfellow, High-Purity Cobalt Metal, material page
    type: datasheet
    url: https://www.goodfellow.com/usa/material/metals/cobalt
  - title: Goodfellow, High-Purity Cobalt Rod, product page
    type: datasheet
    url: https://www.goodfellow.com/usa/cobalt-rod-group
  - title: Goodfellow, Cobalt Foil 0.025 mm, 99.8 %, technical data sheet (SKU 1000005039)
    type: datasheet
    url: https://www.goodfellow.com/usa/technical_data/pdf/download?sku=1000005039
  - title: 'Wikipedia: Cobalt'
    type: database
    url: https://en.wikipedia.org/wiki/Cobalt
  - title: PubChem compound record for cobalt (CID 104730), with HSDB, ECHA and OSHA entries
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Cobalt
  - title: 'USGS Mineral Commodity Summaries 2026: Cobalt'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cobalt.pdf
    year: 2026
  - title: NIST Atomic Weights and Isotopic Compositions, cobalt
    type: database
    url: https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=Co&all=all&ascii=html
  - title: ATSDR Toxic Substances Portal, Cobalt
    type: database
    url: https://wwwn.cdc.gov/TSP/substances/ToxSubstance.aspx?toxid=64
  - title: Fine Metals Corporation, cobalt rod product listing
    type: report
    url: https://finemetalscorp.com/product/cobalt-rod/
gaps:
  - No designation (UNS, EN, AISI, ASTM or trade name) for unalloyed cobalt was printed in any source read in this run. A search for a UNS number returned only cobalt-base alloy standards. Goodfellow's catalogue codes (legacy code CO000190, product code CO00-FL-000290) are supplier codes, not designations, so they are not recorded, and identity.designations is left out.
  - 'Yield strength of unalloyed cobalt was not recorded: the Goodfellow table prints 345-485 MPa with no temper, and the rule is to state the temper for each strength value.'
  - Vickers hardness, saturation magnetization, latent heat of fusion and the hcp to fcc transformation temperature are not canonical names in spores/property-canon.yaml, so they use the snake_case names vickers_hardness, saturation_magnetization, heat_of_fusion and phase_transformation_temperature.
  - Wikipedia prints a density of 8.834 g/cm3 at 20 °C in its infobox, which differs from the 8.90 g/cm3 of the Goodfellow pages and the 8.9 g/cm3 of the rod page. It is not entered, to keep one density per supplier, and the difference is not resolved.
  - Atomic-oxygen erosion, outgassing (total mass loss), cold welding and radiation effects on pure cobalt were not found in the sources read. No NASA or ESA test result for cobalt was opened.
  - Atmospheric corrosion rate, oxide film thickness and high-temperature oxidation rate for pure cobalt were not found as numbers.
  - The Cobalt Institute facts page was fetched but no production, use or supply figure could be read from it, so it is not cited.
  - The NIOSH and OSHA chemical-data pages could not be read directly (short error responses), so their limits are taken from the PubChem record, which prints them.
  - The critical-mineral status is taken from the Goodfellow page; the USGS summary read here does not name the critical-mineral list.
  - Process steps beyond reductive smelting and by-product recovery (refining route, electrowinning) were not read from a primary process source.
  - Electrical and thermal properties at cryogenic temperatures were not looked up; the NIST cryogenic tables are not in this profile.
sources:
  goodfellow-co-metal:
    title: High-Purity Cobalt Metal, Goodfellow material page (Co 99.99 % maximum, 4N), physical, electrical, thermal and mechanical data
    id: Goodfellow Metals, cobalt material page
    url: https://www.goodfellow.com/usa/material/metals/cobalt
    kind: datasheet
    license: Supplier web page, cited not reproduced
  goodfellow-co-rod:
    title: High-Purity Cobalt Rod, Goodfellow product page with material properties for metals
    id: Goodfellow Metals, cobalt rod product page
    url: https://www.goodfellow.com/usa/cobalt-rod-group
    kind: datasheet
    license: Supplier web page, cited not reproduced
  goodfellow-co-foil:
    title: Cobalt Foil/Sheet 0.025 mm x 150 mm x 150 mm, 99.8 % purity, Goodfellow technical data sheet (SKU 1000005039)
    id: Goodfellow SKU 1000005039, Product Code CO00-FL-000290
    url: https://www.goodfellow.com/usa/technical_data/pdf/download?sku=1000005039
    kind: datasheet
    license: Supplier data sheet, cited not reproduced
  wikipedia-co:
    title: Cobalt, Wikipedia (infobox properties, characteristics, alloys and applications)
    id: Wikipedia article Cobalt, CC BY-SA 4.0
    url: https://en.wikipedia.org/wiki/Cobalt
    kind: web
    license: CC BY-SA 4.0, linked not reproduced
  pubchem-co:
    title: PubChem compound record for Cobalt (CID 104730), experimental properties, GHS classification, HSDB and ECHA summaries
    id: CID 104730, CAS 7440-48-4, EC 231-158-0
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/104730/JSON
    kind: database
    license: PubChem (NCBI) record; sections attributed to HSDB, ECHA and others
  usgs-mcs2026-cobalt:
    title: Mineral Commodity Summaries 2026, Cobalt (U.S. Geological Survey, February 2026)
    id: USGS MCS 2026, data for 2025
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cobalt.pdf
    year: 2026
    kind: report
    license: Public domain (USGS)
  nist-atomic-weights:
    title: NIST Atomic Weights and Isotopic Compositions for All Elements, cobalt row
    id: NIST standard atomic weight of Co 58.933 194(4)
    url: https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=Co&all=all&ascii=html
    kind: database
    license: US government data
  atsdr-cobalt:
    title: ATSDR Toxic Substances Portal, Cobalt (CAS 7440-48-4)
    id: ATSDR Toxicological profile summary, Cobalt
    url: https://wwwn.cdc.gov/TSP/substances/ToxSubstance.aspx?toxid=64
    kind: web
    license: US government public health information
  fine-metals-co-rod:
    title: Cobalt Rod, Fine Metals Corporation product listing with specification list
    id: Reseller listing, no standard cited
    url: https://finemetalscorp.com/product/cobalt-rod/
    kind: web
    license: Reseller web page, cited not reproduced
license: CC-BY-4.0
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 26
  unreachable: 3
  caveats: 6
  note: 'Values were read by an AI assistant on 2026-10-26 from the pages and PDFs named in each entry. USGS and the Goodfellow foil data sheet were read from PDF text. Unreachable or unhelpful: the NIOSH and OSHA chemical pages returned short error responses, and the Cobalt Institute facts page gave no usable figure. Caveats: supplier values for density and resistivity differ slightly between pages (for example 62.4 nΩ·m and 6.34 µΩ·cm); the Wikipedia density of 8.834 g/cm3 is not entered; the foil values are for one 0.025 mm foil; the 2025 shares of Congo and Indonesia are USGS estimates; the critical-mineral status rests on one supplier page.'
story:
  recipe:
    line: Cobalt is a single-element metal, Co, with a hexagonal close-packed structure below 417 °C and a face-centred cubic structure above it (Goodfellow). Today it is usually produced as a by-product of copper and nickel mining, and the free element is made by reductive smelting (Wikipedia).
    parts:
      - name: Cobalt
        symbol: Co
        atoms: 1
        atomic_weight: 58.933194
        role: 'The whole material: unalloyed cobalt metal. The NIST standard atomic weight is 58.933 194(4).'
  risk_groups:
    - title: For people
      lead: The EU harmonised classification lists cobalt metal as a skin and respiratory sensitiser, suspected of causing genetic defects, and as a substance that may cause cancer. ECHA notifications differ on the rest.
      level: 2
      verdict: Carcinogen and sensitiser under EU rules
      points:
        - label: Harmonised classification
          line: 'PubChem prints the EU classification under Regulation (EC) No 1272/2008: H317, H334, H341 and H350, signal word Danger.'
        - label: Notifications
          line: Of 2,768 company reports to ECHA, one says cobalt does not meet GHS criteria. Among reports that gave codes, H317 is given by more than 99.9 %, H302 by 65.2 % and H330 by 23.4 %.
    - title: If it fails
      lead: The failure routes printed in the sources are fire from fine powder and acid attack with hydrogen release. No space exposure data for pure cobalt was found.
      points:
        - label: Fine powder
          line: Finely divided cobalt can ignite in air, and dust can form explosive mixtures in air.
        - label: Acid
          line: Dilute hydrochloric, sulfuric and nitric acids dissolve cobalt, and the reaction releases flammable and explosive hydrogen.
    - title: Handling and storage
      points:
        - label: Dust limits
          line: The OSHA limit for cobalt metal dust and fume is 0.1 mg/m3 and the NIOSH limit is 0.05 mg/m3, both as Co.
        - label: Keep fine cobalt apart
          line: Keep fine cobalt away from air, oxidising agents, acetylene and ammonium nitrate.
  why: 'Cobalt is a hard, ferromagnetic metal. Goodfellow gives its density as 8.90 g/cm3 at 20 °C and its melting point as 1495 °C, and it stays ferromagnetic up to its Curie temperature of 1115 °C. Its thermal conductivity is 100 W/(m·K) in the Goodfellow rod data. It is used mainly as an alloy element: superalloys took 51 % of US cobalt use in 2025, mainly for aircraft gas turbine engines (USGS), and the cobalt content of lithium-ion batteries is the leading global use. Congo (Kinshasa) mined an estimated 73 % of world cobalt in 2025.'
  uses:
    - where: Batteries
      line: The cobalt content of lithium-ion batteries is the leading global use of cobalt, according to the USGS. Cobalt-free cells that use iron and phosphorus held a significant share of the market in China.
    - where: Aircraft engines
      line: In the United States, superalloys took 51 % of cobalt use in 2025, mainly for aircraft gas turbine engines. Goodfellow adds nozzle guide vanes, combustion liners and first-stage turbine blades as cobalt-base alloy parts.
    - where: Satellite electronics
      line: Wikipedia says cobalt alloys are used in connectors, thermal switches and microsensors that must endure extreme temperatures, vibration and radiation, conditions typical in satellites.
    - where: Magnets and actuators
      line: Samarium-cobalt magnets outperform NdFeB above about 150 °C and in corrosive environments, which Goodfellow gives as the reason for their use in high-temperature motors, sensors and aerospace actuators.
  can_do:
    - label: Carry heat
      value: 100 W/(m·K)
      benchmark: thermal_conductivity
      line: The Goodfellow rod data gives 100 W/(m·K) for 0 to 100 °C. A reseller listing gives 1.0 W/(cm·K) at 298.2 K, which is the same order of magnitude.
    - label: Stay magnetic when hot
      value: 1115 °C Curie temperature
      benchmark: curie_temperature
      line: Cobalt stops being ferromagnetic only at its Curie temperature of 1115 °C, which Goodfellow describes as the highest of any ferromagnetic element.
    - label: Weight
      value: 8.90 g/cm3
      benchmark: density
      line: The density is 8.90 g/cm3 at 20 °C on the Goodfellow metal page, and 8.9 g/cm3 on the rod page.
    - label: Melt
      value: 1495 °C melting point
      benchmark: melting_point
      line: The melting point is 1495 °C (1768 K) on the Goodfellow page. PubChem prints the boiling point as 2,927 °C in its HSDB entry, against 2870 °C on the Goodfellow page.
    - label: Strength in two tempers (foil)
      value: 1135 MPa hard, 760 MPa soft
      benchmark: ultimate_tensile_strength
      line: A 0.025 mm cobalt foil of 99.8 % purity has tensile strength 1135 MPa in the hard temper and 760 MPa in the soft temper, with Vickers hardness 320 and 170.
    - label: Expansion
      value: 12.5 ppm/K
      benchmark: cte
      line: The coefficient of thermal expansion is 12.5 ppm/K from 0 to 100 °C on the Goodfellow rod page, and 12.9 ppm/K at 20 °C in Wikipedia.
  compare: Goodfellow describes the density of cobalt as intermediate between those of iron and nickel, and its thermal conductivity as similar to both. Iron and nickel are similar metals, so read the table rows as examples of the same class, not as a ranking.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Thermal conductivity
      benchmark: thermal_conductivity
    - label: Melting point
      benchmark: melting_point
  handling:
    - Specify the temper, since the foil tensile strength is 1135 MPa hard and 760 MPa soft.
    - Treat fine powder as pyrophoric, and keep it away from air, acetylene, oxidisers and ammonium nitrate.
    - Keep metal dust and fume below 0.1 mg/m3 (OSHA) and 0.05 mg/m3 (NIOSH), both as Co.
  good_for:
    - 'High-temperature magnets: a Curie temperature of 1115 °C, and samarium-cobalt magnets that outperform NdFeB above about 150 °C (Goodfellow).'
    - 'Hot alloys: cobalt-base superalloys for aircraft gas turbine engines (USGS).'
    - 'Battery cathodes: the leading global use of cobalt, according to the USGS.'
  watch_out:
    - 'Supply is concentrated: Congo (Kinshasa) mined an estimated 73 % of world cobalt in 2025, and export quotas run to 96,600 t per year in 2026 and 2027.'
    - The EU classification includes H350 (may cause cancer) and H317 (allergic skin reaction).
    - Fine powder can ignite in air, and acid attack releases hydrogen.
    - No atomic-oxygen, outgassing or radiation data for pure cobalt in space was found.
  verdict: Cobalt is a dense, hard, high-temperature ferromagnetic metal with a melting point of 1495 °C and a Curie temperature of 1115 °C. Its main roles are as an alloy element in magnets, superalloys and battery cathodes, and its supply is concentrated in Congo (Kinshasa). The EU classifies the metal as a carcinogen and a sensitiser, and fine powder is pyrophoric. The profile has no space outgassing, atomic-oxygen or designation data for pure cobalt.