{
 "note": "Cross-source corroboration of world production. BGS national returns SUMMED vs the USGS world estimate. These are independent COMPILATIONS but NOT independent MEASUREMENTS - both rest largely on the same national returns, so agreement raises confidence in our pairing and units, not proof that a figure is true; an uncorroborated number is not thereby wrong. ratio = median(BGS sum / USGS world) over the overlapping years. corroborated = within ~10%. A \"not_comparable\" row is usually a basis or stage difference, not an error: the pairing is stated explicitly and the reason recorded, because an unexplained ratio invites someone to fix a number that was never wrong.",
 "method": "Pairings are declared in build_pairing.py, never inferred at run time. Joining on material alone would compare gross ore against contained metal.",
 "summary": {
  "agrees_within_10pct": 35,
  "not_comparable": 11,
  "agrees_within_25pct": 7
 },
 "n_materials": 53,
 "rows": [
  {
   "material": "antimony",
   "bgs_form": "antimony, mine",
   "usgs_series": "world production",
   "ratio": 1.011,
   "ratio_spread_p10_p90": 0.328,
   "years": [
    2005,
    2019
   ],
   "n_years": 15,
   "bgs_reporters_median": 17,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.755
    },
    {
     "iso": "TJK",
     "share_of_bgs_sum": 0.076
    },
    {
     "iso": "RUS",
     "share_of_bgs_sum": 0.052
    },
    {
     "iso": "BOL",
     "share_of_bgs_sum": 0.024
    }
   ]
  },
  {
   "material": "arsenic",
   "bgs_form": "arsenic, white",
   "usgs_series": "world production",
   "ratio": 1.031,
   "ratio_spread_p10_p90": 0.326,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 7,
   "status": "agrees_within_10pct",
   "census_plausible": false,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.538
    },
    {
     "iso": "PER",
     "share_of_bgs_sum": 0.205
    },
    {
     "iso": "MAR",
     "share_of_bgs_sum": 0.115
    },
    {
     "iso": "CHL",
     "share_of_bgs_sum": 0.062
    }
   ]
  },
  {
   "material": "asbestos",
   "bgs_form": "asbestos",
   "usgs_series": "world production",
   "ratio": 0.973,
   "ratio_spread_p10_p90": 0.174,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 5,
   "status": "agrees_within_10pct",
   "census_plausible": false,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "RUS",
     "share_of_bgs_sum": 0.54
    },
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.171
    },
    {
     "iso": "KAZ",
     "share_of_bgs_sum": 0.149
    },
    {
     "iso": "BRA",
     "share_of_bgs_sum": 0.136
    }
   ]
  },
  {
   "material": "baryte",
   "bgs_form": "barytes",
   "usgs_series": "world production",
   "ratio": 1.044,
   "ratio_spread_p10_p90": 0.155,
   "years": [
    2005,
    2021
   ],
   "n_years": 17,
   "bgs_reporters_median": 35,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.411
    },
    {
     "iso": "IND",
     "share_of_bgs_sum": 0.19
    },
    {
     "iso": "MAR",
     "share_of_bgs_sum": 0.094
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.056
    }
   ]
  },
  {
   "material": "bauxite",
   "bgs_form": "bauxite",
   "usgs_series": "world production",
   "ratio": 0.99,
   "ratio_spread_p10_p90": 0.11,
   "years": [
    2005,
    2021
   ],
   "n_years": 17,
   "bgs_reporters_median": 31,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "AUS",
     "share_of_bgs_sum": 0.298
    },
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.16
    },
    {
     "iso": "GIN",
     "share_of_bgs_sum": 0.13
    },
    {
     "iso": "BRA",
     "share_of_bgs_sum": 0.119
    }
   ]
  },
  {
   "material": "beryllium",
   "bgs_form": "beryl",
   "usgs_series": "world production",
   "ratio": 24.977,
   "ratio_spread_p10_p90": 2.408,
   "years": [
    2005,
    2021
   ],
   "n_years": 17,
   "bgs_reporters_median": 6,
   "status": "not_comparable",
   "census_plausible": false,
   "reason": "BGS counts BERYL (the ore mineral); USGS counts contained beryllium. Beryl is roughly 4% Be.",
   "bgs_top_reporters": [
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.755
    },
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.173
    },
    {
     "iso": "BRA",
     "share_of_bgs_sum": 0.028
    },
    {
     "iso": "MOZ",
     "share_of_bgs_sum": 0.024
    }
   ]
  },
  {
   "material": "bismuth",
   "bgs_form": "bismuth, mine",
   "usgs_series": "world production",
   "ratio": 0.563,
   "ratio_spread_p10_p90": 0.472,
   "years": [
    2005,
    2013
   ],
   "n_years": 9,
   "bgs_reporters_median": 8,
   "status": "not_comparable",
   "census_plausible": true,
   "reason": "Unresolved. Both sides are now MINE output (the USGS world mine series entered the cube on 16 Sep 2026; it ends in 2013, so only 2005-2013 overlap), and BGS national returns sum to about half of it. The earlier note blamed a stage mismatch - true only while the USGS side was refinery production.",
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.422
    },
    {
     "iso": "MEX",
     "share_of_bgs_sum": 0.25
    },
    {
     "iso": "PER",
     "share_of_bgs_sum": 0.131
    },
    {
     "iso": "JPN",
     "share_of_bgs_sum": 0.115
    }
   ]
  },
  {
   "material": "boron",
   "bgs_form": "borates",
   "usgs_series": "world production",
   "ratio": 1.281,
   "ratio_spread_p10_p90": 0.645,
   "years": [
    2005,
    2013
   ],
   "n_years": 9,
   "bgs_reporters_median": 10,
   "status": "not_comparable",
   "census_plausible": true,
   "reason": "BGS counts borate MINERALS (gross); USGS reports boron content.",
   "bgs_top_reporters": [
    {
     "iso": "TUR",
     "share_of_bgs_sum": 0.398
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.227
    },
    {
     "iso": "ARG",
     "share_of_bgs_sum": 0.111
    },
    {
     "iso": "CHL",
     "share_of_bgs_sum": 0.097
    }
   ]
  },
  {
   "material": "bromine",
   "bgs_form": "bromine",
   "usgs_series": "world production",
   "ratio": 1.596,
   "ratio_spread_p10_p90": 0.47,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 9,
   "status": "not_comparable",
   "census_plausible": true,
   "reason": "Unresolved: likely a compound-vs-element basis difference.",
   "bgs_top_reporters": [
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.362
    },
    {
     "iso": "ISR",
     "share_of_bgs_sum": 0.274
    },
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.172
    },
    {
     "iso": "JOR",
     "share_of_bgs_sum": 0.145
    }
   ]
  },
  {
   "material": "cadmium",
   "bgs_form": "cadmium",
   "usgs_series": "world production",
   "ratio": 0.997,
   "ratio_spread_p10_p90": 0.138,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 18,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.33
    },
    {
     "iso": "KOR",
     "share_of_bgs_sum": 0.171
    },
    {
     "iso": "JPN",
     "share_of_bgs_sum": 0.086
    },
    {
     "iso": "CAN",
     "share_of_bgs_sum": 0.069
    }
   ]
  },
  {
   "material": "cement",
   "bgs_form": "cement, finished",
   "usgs_series": "world production",
   "ratio": 0.066,
   "ratio_spread_p10_p90": 0.058,
   "years": [
    2005,
    2021
   ],
   "n_years": 17,
   "bgs_reporters_median": 32,
   "status": "not_comparable",
   "census_plausible": true,
   "reason": "RESOLVED - not a unit slip: both series are in tonnes. It is a coverage hole. BGS cement has ~33 reporters led by Turkey, Germany, Poland, Italy and Spain; CHINA AND INDIA ARE ABSENT, and China alone is ~2.4 of the ~4.2 billion tonne world total. The BGS cement panel is a Europe-weighted sub-panel, not a world census, so its sum must never be used as a world denominator.",
   "bgs_top_reporters": [
    {
     "iso": "TUR",
     "share_of_bgs_sum": 0.237
    },
    {
     "iso": "DEU",
     "share_of_bgs_sum": 0.119
    },
    {
     "iso": "ITA",
     "share_of_bgs_sum": 0.108
    },
    {
     "iso": "ESP",
     "share_of_bgs_sum": 0.093
    }
   ]
  },
  {
   "material": "chromium",
   "bgs_form": "chromium ores and concentrates",
   "usgs_series": "world production",
   "ratio": 2.822,
   "ratio_spread_p10_p90": 0.86,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 19,
   "status": "not_comparable",
   "census_plausible": true,
   "reason": "BGS counts chromite ORE at gross weight; USGS counts contained chromium.",
   "bgs_top_reporters": [
    {
     "iso": "ZAF",
     "share_of_bgs_sum": 0.444
    },
    {
     "iso": "KAZ",
     "share_of_bgs_sum": 0.181
    },
    {
     "iso": "IND",
     "share_of_bgs_sum": 0.122
    },
    {
     "iso": "TUR",
     "share_of_bgs_sum": 0.089
    }
   ]
  },
  {
   "material": "cobalt",
   "bgs_form": "cobalt, mine",
   "usgs_series": "world production",
   "ratio": 1.048,
   "ratio_spread_p10_p90": 0.562,
   "years": [
    2005,
    2021
   ],
   "n_years": 17,
   "bgs_reporters_median": 19,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "COD",
     "share_of_bgs_sum": 0.605
    },
    {
     "iso": "CAN",
     "share_of_bgs_sum": 0.053
    },
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.05
    },
    {
     "iso": "AUS",
     "share_of_bgs_sum": 0.048
    }
   ]
  },
  {
   "material": "copper",
   "bgs_form": "copper, mine",
   "usgs_series": "world production",
   "ratio": 0.999,
   "ratio_spread_p10_p90": 0.013,
   "years": [
    2005,
    2020
   ],
   "n_years": 16,
   "bgs_reporters_median": 54,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHL",
     "share_of_bgs_sum": 0.312
    },
    {
     "iso": "PER",
     "share_of_bgs_sum": 0.091
    },
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.08
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.07
    }
   ]
  },
  {
   "material": "diatomite",
   "bgs_form": "diatomite",
   "usgs_series": "world production",
   "ratio": 0.915,
   "ratio_spread_p10_p90": 0.123,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 27,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.364
    },
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.169
    },
    {
     "iso": "DNK",
     "share_of_bgs_sum": 0.061
    },
    {
     "iso": "MEX",
     "share_of_bgs_sum": 0.047
    }
   ]
  },
  {
   "material": "feldspar",
   "bgs_form": "feldspar",
   "usgs_series": "world production",
   "ratio": 1.146,
   "ratio_spread_p10_p90": 0.316,
   "years": [
    2005,
    2019
   ],
   "n_years": 15,
   "bgs_reporters_median": 52,
   "status": "agrees_within_25pct",
   "census_plausible": true,
   "reason": "Within compilation tolerance. No structural basis difference identified; the two bodies revise on different schedules and BGS country coverage varies by year.",
   "bgs_top_reporters": [
    {
     "iso": "TUR",
     "share_of_bgs_sum": 0.3
    },
    {
     "iso": "ITA",
     "share_of_bgs_sum": 0.167
    },
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.096
    },
    {
     "iso": "IND",
     "share_of_bgs_sum": 0.079
    }
   ]
  },
  {
   "material": "fluorspar",
   "bgs_form": "fluorspar",
   "usgs_series": "world production",
   "ratio": 0.988,
   "ratio_spread_p10_p90": 0.193,
   "years": [
    2005,
    2020
   ],
   "n_years": 16,
   "bgs_reporters_median": 24,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.637
    },
    {
     "iso": "MEX",
     "share_of_bgs_sum": 0.152
    },
    {
     "iso": "MNG",
     "share_of_bgs_sum": 0.041
    },
    {
     "iso": "ZAF",
     "share_of_bgs_sum": 0.033
    }
   ]
  },
  {
   "material": "gallium",
   "bgs_form": "gallium, primary",
   "usgs_series": "world production",
   "ratio": 0.813,
   "ratio_spread_p10_p90": 0.783,
   "years": [
    2007,
    2021
   ],
   "n_years": 15,
   "bgs_reporters_median": 5,
   "status": "agrees_within_25pct",
   "census_plausible": false,
   "reason": "BGS gallium coverage is thin and USGS publishes an estimate rather than a census; neither side is a measured world total.",
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.859
    },
    {
     "iso": "RUS",
     "share_of_bgs_sum": 0.046
    },
    {
     "iso": "KAZ",
     "share_of_bgs_sum": 0.028
    },
    {
     "iso": "DEU",
     "share_of_bgs_sum": 0.022
    }
   ]
  },
  {
   "material": "germanium",
   "bgs_form": "germanium metal",
   "usgs_series": "world production",
   "ratio": 0.835,
   "ratio_spread_p10_p90": 0.338,
   "years": [
    2005,
    2020
   ],
   "n_years": 16,
   "bgs_reporters_median": 3,
   "status": "agrees_within_25pct",
   "census_plausible": false,
   "reason": "BGS carries only 3-4 reporting countries for germanium metal, so its sum is not a world total; USGS states outright that reliable world estimates cannot be made. The near-agreement here is coincidence, not corroboration - this is the material that prompted the whole check.",
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.871
    },
    {
     "iso": "FIN",
     "share_of_bgs_sum": 0.051
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.035
    },
    {
     "iso": "RUS",
     "share_of_bgs_sum": 0.034
    }
   ]
  },
  {
   "material": "gold",
   "bgs_form": "gold, mine",
   "usgs_series": "world production",
   "ratio": 1.015,
   "ratio_spread_p10_p90": 0.044,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 98,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.125
    },
    {
     "iso": "AUS",
     "share_of_bgs_sum": 0.094
    },
    {
     "iso": "RUS",
     "share_of_bgs_sum": 0.08
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.076
    }
   ]
  },
  {
   "material": "graphite",
   "bgs_form": "graphite",
   "usgs_series": "world production",
   "ratio": 1.268,
   "ratio_spread_p10_p90": 1.353,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 16,
   "status": "not_comparable",
   "census_plausible": true,
   "reason": "Unresolved: natural-graphite scope differs between the two.",
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.741
    },
    {
     "iso": "IND",
     "share_of_bgs_sum": 0.066
    },
    {
     "iso": "BRA",
     "share_of_bgs_sum": 0.049
    },
    {
     "iso": "BIH",
     "share_of_bgs_sum": 0.029
    }
   ]
  },
  {
   "material": "gypsum",
   "bgs_form": "gypsum and plaster",
   "usgs_series": "world production",
   "ratio": 1.031,
   "ratio_spread_p10_p90": 0.417,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 84,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.16
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.114
    },
    {
     "iso": "IRN",
     "share_of_bgs_sum": 0.092
    },
    {
     "iso": "THA",
     "share_of_bgs_sum": 0.068
    }
   ]
  },
  {
   "material": "indium",
   "bgs_form": "indium, refinery",
   "usgs_series": "world production",
   "ratio": 0.93,
   "ratio_spread_p10_p90": 0.124,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 11,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.603
    },
    {
     "iso": "KOR",
     "share_of_bgs_sum": 0.128
    },
    {
     "iso": "JPN",
     "share_of_bgs_sum": 0.089
    },
    {
     "iso": "CAN",
     "share_of_bgs_sum": 0.079
    }
   ]
  },
  {
   "material": "iodine",
   "bgs_form": "iodine",
   "usgs_series": "world production",
   "ratio": 1.066,
   "ratio_spread_p10_p90": 0.052,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 9,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHL",
     "share_of_bgs_sum": 0.6
    },
    {
     "iso": "JPN",
     "share_of_bgs_sum": 0.303
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.044
    },
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.019
    }
   ]
  },
  {
   "material": "iron",
   "bgs_form": "iron ore",
   "usgs_series": "world production",
   "ratio": 0.869,
   "ratio_spread_p10_p90": 0.175,
   "years": [
    2005,
    2021
   ],
   "n_years": 17,
   "bgs_reporters_median": 46,
   "status": "agrees_within_25pct",
   "census_plausible": true,
   "reason": "Iron ore scope differs: crude-ore vs usable-ore reporting is not consistent between the two bodies.",
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.366
    },
    {
     "iso": "AUS",
     "share_of_bgs_sum": 0.222
    },
    {
     "iso": "BRA",
     "share_of_bgs_sum": 0.138
    },
    {
     "iso": "IND",
     "share_of_bgs_sum": 0.068
    }
   ]
  },
  {
   "material": "lead",
   "bgs_form": "lead, mine",
   "usgs_series": "world production",
   "ratio": 1.007,
   "ratio_spread_p10_p90": 0.079,
   "years": [
    2005,
    2021
   ],
   "n_years": 17,
   "bgs_reporters_median": 46,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.439
    },
    {
     "iso": "AUS",
     "share_of_bgs_sum": 0.133
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.08
    },
    {
     "iso": "PER",
     "share_of_bgs_sum": 0.065
    }
   ]
  },
  {
   "material": "lithium",
   "bgs_form": "lithium minerals",
   "usgs_series": "world production",
   "ratio": 0.96,
   "ratio_spread_p10_p90": 0.372,
   "years": [
    2005,
    2021
   ],
   "n_years": 17,
   "bgs_reporters_median": 7,
   "status": "agrees_within_10pct",
   "census_plausible": false,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "AUS",
     "share_of_bgs_sum": 0.778
    },
    {
     "iso": "CHL",
     "share_of_bgs_sum": 0.084
    },
    {
     "iso": "PRT",
     "share_of_bgs_sum": 0.036
    },
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.027
    }
   ]
  },
  {
   "material": "magnesium",
   "bgs_form": "magnesite",
   "usgs_series": "world production",
   "ratio": 1.104,
   "ratio_spread_p10_p90": 0.25,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 23,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.59
    },
    {
     "iso": "RUS",
     "share_of_bgs_sum": 0.099
    },
    {
     "iso": "TUR",
     "share_of_bgs_sum": 0.082
    },
    {
     "iso": "BRA",
     "share_of_bgs_sum": 0.056
    }
   ]
  },
  {
   "material": "manganese",
   "bgs_form": "manganese ore",
   "usgs_series": "world production",
   "ratio": 2.738,
   "ratio_spread_p10_p90": 0.721,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 27,
   "status": "not_comparable",
   "census_plausible": true,
   "reason": "BGS counts manganese ORE at gross weight; USGS counts CONTAINED manganese. Ore grades ~30-50% Mn, which is the whole ratio.",
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.276
    },
    {
     "iso": "ZAF",
     "share_of_bgs_sum": 0.163
    },
    {
     "iso": "AUS",
     "share_of_bgs_sum": 0.137
    },
    {
     "iso": "GAB",
     "share_of_bgs_sum": 0.109
    }
   ]
  },
  {
   "material": "mercury",
   "bgs_form": "mercury",
   "usgs_series": "world production",
   "ratio": 1.012,
   "ratio_spread_p10_p90": 0.165,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 9,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.799
    },
    {
     "iso": "MEX",
     "share_of_bgs_sum": 0.051
    },
    {
     "iso": "TJK",
     "share_of_bgs_sum": 0.047
    },
    {
     "iso": "KGZ",
     "share_of_bgs_sum": 0.041
    }
   ]
  },
  {
   "material": "mica",
   "bgs_form": "mica",
   "usgs_series": "world production",
   "ratio": 0.794,
   "ratio_spread_p10_p90": 0.611,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 20,
   "status": "not_comparable",
   "census_plausible": true,
   "reason": "Unresolved: sheet vs scrap/flake mica scope differs.",
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.275
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.167
    },
    {
     "iso": "BRA",
     "share_of_bgs_sum": 0.09
    },
    {
     "iso": "KOR",
     "share_of_bgs_sum": 0.077
    }
   ]
  },
  {
   "material": "molybdenum",
   "bgs_form": "molybdenum, mine",
   "usgs_series": "world production",
   "ratio": 1.005,
   "ratio_spread_p10_p90": 0.041,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 15,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.384
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.199
    },
    {
     "iso": "CHL",
     "share_of_bgs_sum": 0.181
    },
    {
     "iso": "PER",
     "share_of_bgs_sum": 0.086
    }
   ]
  },
  {
   "material": "nickel",
   "bgs_form": "nickel, mine",
   "usgs_series": "world production",
   "ratio": 0.985,
   "ratio_spread_p10_p90": 0.155,
   "years": [
    2005,
    2020
   ],
   "n_years": 16,
   "bgs_reporters_median": 27,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "IDN",
     "share_of_bgs_sum": 0.235
    },
    {
     "iso": "RUS",
     "share_of_bgs_sum": 0.126
    },
    {
     "iso": "PHL",
     "share_of_bgs_sum": 0.12
    },
    {
     "iso": "CAN",
     "share_of_bgs_sum": 0.101
    }
   ]
  },
  {
   "material": "perlite",
   "bgs_form": "perlite",
   "usgs_series": "world production",
   "ratio": 1.065,
   "ratio_spread_p10_p90": 0.822,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 19,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.248
    },
    {
     "iso": "GRC",
     "share_of_bgs_sum": 0.227
    },
    {
     "iso": "TUR",
     "share_of_bgs_sum": 0.212
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.115
    }
   ]
  },
  {
   "material": "phosphate",
   "bgs_form": "phosphate rock",
   "usgs_series": "world production",
   "ratio": 1.009,
   "ratio_spread_p10_p90": 0.034,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 36,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.421
    },
    {
     "iso": "MAR",
     "share_of_bgs_sum": 0.14
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.129
    },
    {
     "iso": "RUS",
     "share_of_bgs_sum": 0.055
    }
   ]
  },
  {
   "material": "platinum",
   "bgs_form": "platinum group metals, mine",
   "usgs_series": "world production",
   "ratio": 0.99,
   "ratio_spread_p10_p90": 0.189,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 11,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "ZAF",
     "share_of_bgs_sum": 0.567
    },
    {
     "iso": "RUS",
     "share_of_bgs_sum": 0.277
    },
    {
     "iso": "CAN",
     "share_of_bgs_sum": 0.055
    },
    {
     "iso": "ZWE",
     "share_of_bgs_sum": 0.048
    }
   ]
  },
  {
   "material": "potash",
   "bgs_form": "potash",
   "usgs_series": "world production",
   "ratio": 1.006,
   "ratio_spread_p10_p90": 0.055,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 12,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CAN",
     "share_of_bgs_sum": 0.297
    },
    {
     "iso": "RUS",
     "share_of_bgs_sum": 0.176
    },
    {
     "iso": "BLR",
     "share_of_bgs_sum": 0.15
    },
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.112
    }
   ]
  },
  {
   "material": "rare_earths",
   "bgs_form": "rare earth oxides",
   "usgs_series": "world production",
   "ratio": 1.067,
   "ratio_spread_p10_p90": 0.263,
   "years": [
    2005,
    2020
   ],
   "n_years": 16,
   "bgs_reporters_median": 6,
   "status": "agrees_within_10pct",
   "census_plausible": false,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.855
    },
    {
     "iso": "MMR",
     "share_of_bgs_sum": 0.049
    },
    {
     "iso": "AUS",
     "share_of_bgs_sum": 0.04
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.025
    }
   ]
  },
  {
   "material": "rhenium",
   "bgs_form": "rhenium",
   "usgs_series": "world production",
   "ratio": 0.975,
   "ratio_spread_p10_p90": 0.238,
   "years": [
    2006,
    2022
   ],
   "n_years": 17,
   "bgs_reporters_median": 7,
   "status": "agrees_within_10pct",
   "census_plausible": false,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHL",
     "share_of_bgs_sum": 0.537
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.156
    },
    {
     "iso": "POL",
     "share_of_bgs_sum": 0.128
    },
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.048
    }
   ]
  },
  {
   "material": "salt",
   "bgs_form": "salt",
   "usgs_series": "world production",
   "ratio": 0.953,
   "ratio_spread_p10_p90": 0.114,
   "years": [
    2005,
    2021
   ],
   "n_years": 17,
   "bgs_reporters_median": 101,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.244
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.135
    },
    {
     "iso": "IND",
     "share_of_bgs_sum": 0.092
    },
    {
     "iso": "DEU",
     "share_of_bgs_sum": 0.062
    }
   ]
  },
  {
   "material": "selenium",
   "bgs_form": "selenium, refined",
   "usgs_series": "world production",
   "ratio": 1.169,
   "ratio_spread_p10_p90": 0.492,
   "years": [
    2005,
    2020
   ],
   "n_years": 16,
   "bgs_reporters_median": 16,
   "status": "agrees_within_25pct",
   "census_plausible": true,
   "reason": "Within compilation tolerance; refinery-output coverage differs by year.",
   "bgs_top_reporters": [
    {
     "iso": "JPN",
     "share_of_bgs_sum": 0.253
    },
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.196
    },
    {
     "iso": "DEU",
     "share_of_bgs_sum": 0.166
    },
    {
     "iso": "BEL",
     "share_of_bgs_sum": 0.067
    }
   ]
  },
  {
   "material": "silver",
   "bgs_form": "silver, mine",
   "usgs_series": "world production",
   "ratio": 1.006,
   "ratio_spread_p10_p90": 0.105,
   "years": [
    2005,
    2021
   ],
   "n_years": 17,
   "bgs_reporters_median": 68,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "MEX",
     "share_of_bgs_sum": 0.207
    },
    {
     "iso": "PER",
     "share_of_bgs_sum": 0.148
    },
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.13
    },
    {
     "iso": "AUS",
     "share_of_bgs_sum": 0.066
    }
   ]
  },
  {
   "material": "strontium",
   "bgs_form": "strontium minerals",
   "usgs_series": "world production",
   "ratio": 1.016,
   "ratio_spread_p10_p90": 0.43,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 6,
   "status": "agrees_within_10pct",
   "census_plausible": false,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "ESP",
     "share_of_bgs_sum": 0.357
    },
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.276
    },
    {
     "iso": "IRN",
     "share_of_bgs_sum": 0.206
    },
    {
     "iso": "MEX",
     "share_of_bgs_sum": 0.137
    }
   ]
  },
  {
   "material": "talc",
   "bgs_form": "talc",
   "usgs_series": "world production",
   "ratio": 0.87,
   "ratio_spread_p10_p90": 0.193,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 36,
   "status": "agrees_within_25pct",
   "census_plausible": true,
   "reason": "Within compilation tolerance; talc/pyrophyllite scope differs slightly.",
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.283
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.098
    },
    {
     "iso": "KOR",
     "share_of_bgs_sum": 0.089
    },
    {
     "iso": "BRA",
     "share_of_bgs_sum": 0.088
    }
   ]
  },
  {
   "material": "tantalum",
   "bgs_form": "tantalum and niobium minerals",
   "usgs_series": "world production",
   "ratio": 122.8,
   "ratio_spread_p10_p90": 171.599,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 6,
   "status": "not_comparable",
   "census_plausible": false,
   "reason": "BGS publishes tantalum AND niobium minerals as one gross-ore series; USGS publishes contained tantalum alone. Different numerator and different basis.",
   "bgs_top_reporters": [
    {
     "iso": "BRA",
     "share_of_bgs_sum": 0.929
    },
    {
     "iso": "CAN",
     "share_of_bgs_sum": 0.057
    },
    {
     "iso": "RWA",
     "share_of_bgs_sum": 0.006
    },
    {
     "iso": "COD",
     "share_of_bgs_sum": 0.006
    }
   ]
  },
  {
   "material": "tellurium",
   "bgs_form": "tellurium, refined",
   "usgs_series": "world production",
   "ratio": 0.943,
   "ratio_spread_p10_p90": 0.491,
   "years": [
    2013,
    2020
   ],
   "n_years": 8,
   "bgs_reporters_median": 6,
   "status": "agrees_within_10pct",
   "census_plausible": false,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.652
    },
    {
     "iso": "JPN",
     "share_of_bgs_sum": 0.089
    },
    {
     "iso": "RUS",
     "share_of_bgs_sum": 0.087
    },
    {
     "iso": "SWE",
     "share_of_bgs_sum": 0.076
    }
   ]
  },
  {
   "material": "tin",
   "bgs_form": "tin, mine",
   "usgs_series": "world production",
   "ratio": 1.028,
   "ratio_spread_p10_p90": 0.284,
   "years": [
    2005,
    2021
   ],
   "n_years": 17,
   "bgs_reporters_median": 24,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.353
    },
    {
     "iso": "IDN",
     "share_of_bgs_sum": 0.267
    },
    {
     "iso": "PER",
     "share_of_bgs_sum": 0.089
    },
    {
     "iso": "MMR",
     "share_of_bgs_sum": 0.076
    }
   ]
  },
  {
   "material": "titanium",
   "bgs_form": "titanium minerals",
   "usgs_series": "world production",
   "ratio": 1.455,
   "ratio_spread_p10_p90": 0.425,
   "years": [
    2005,
    2020
   ],
   "n_years": 16,
   "bgs_reporters_median": 19,
   "status": "not_comparable",
   "census_plausible": true,
   "reason": "BGS counts titanium MINERALS (ilmenite + rutile, gross); USGS reports on a TiO2-content basis.",
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.207
    },
    {
     "iso": "CAN",
     "share_of_bgs_sum": 0.183
    },
    {
     "iso": "AUS",
     "share_of_bgs_sum": 0.141
    },
    {
     "iso": "ZAF",
     "share_of_bgs_sum": 0.1
    }
   ]
  },
  {
   "material": "tungsten",
   "bgs_form": "tungsten, mine",
   "usgs_series": "world production",
   "ratio": 1.019,
   "ratio_spread_p10_p90": 0.119,
   "years": [
    2005,
    2019
   ],
   "n_years": 15,
   "bgs_reporters_median": 20,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.802
    },
    {
     "iso": "RUS",
     "share_of_bgs_sum": 0.052
    },
    {
     "iso": "VNM",
     "share_of_bgs_sum": 0.024
    },
    {
     "iso": "CAN",
     "share_of_bgs_sum": 0.022
    }
   ]
  },
  {
   "material": "vanadium",
   "bgs_form": "vanadium, mine",
   "usgs_series": "world production",
   "ratio": 1.02,
   "ratio_spread_p10_p90": 0.193,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 4,
   "status": "agrees_within_10pct",
   "census_plausible": false,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.52
    },
    {
     "iso": "ZAF",
     "share_of_bgs_sum": 0.229
    },
    {
     "iso": "RUS",
     "share_of_bgs_sum": 0.213
    },
    {
     "iso": "BRA",
     "share_of_bgs_sum": 0.03
    }
   ]
  },
  {
   "material": "wollastonite",
   "bgs_form": "wollastonite",
   "usgs_series": "world production",
   "ratio": 1.186,
   "ratio_spread_p10_p90": 0.995,
   "years": [
    2005,
    2023
   ],
   "n_years": 19,
   "bgs_reporters_median": 7,
   "status": "agrees_within_25pct",
   "census_plausible": false,
   "reason": "Within compilation tolerance; few producers, so one country revision moves the ratio noticeably.",
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.696
    },
    {
     "iso": "IND",
     "share_of_bgs_sum": 0.134
    },
    {
     "iso": "MEX",
     "share_of_bgs_sum": 0.08
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.066
    }
   ]
  },
  {
   "material": "zinc",
   "bgs_form": "zinc, mine",
   "usgs_series": "world production",
   "ratio": 1.006,
   "ratio_spread_p10_p90": 0.104,
   "years": [
    2005,
    2022
   ],
   "n_years": 18,
   "bgs_reporters_median": 51,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "CHN",
     "share_of_bgs_sum": 0.32
    },
    {
     "iso": "PER",
     "share_of_bgs_sum": 0.112
    },
    {
     "iso": "AUS",
     "share_of_bgs_sum": 0.109
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.062
    }
   ]
  },
  {
   "material": "zirconium",
   "bgs_form": "zirconium minerals",
   "usgs_series": "world production",
   "ratio": 0.949,
   "ratio_spread_p10_p90": 0.189,
   "years": [
    2005,
    2021
   ],
   "n_years": 17,
   "bgs_reporters_median": 16,
   "status": "agrees_within_10pct",
   "census_plausible": true,
   "reason": null,
   "bgs_top_reporters": [
    {
     "iso": "AUS",
     "share_of_bgs_sum": 0.411
    },
    {
     "iso": "ZAF",
     "share_of_bgs_sum": 0.282
    },
    {
     "iso": "USA",
     "share_of_bgs_sum": 0.071
    },
    {
     "iso": "IDN",
     "share_of_bgs_sum": 0.046
    }
   ]
  }
 ],
 "corrections": [
  {
   "material": "cobalt",
   "withdrawn_on": "2026-09-16",
   "was": "Not comparable (ratio 0.60), \"resolved\" as DR Congo artisanal output missing from BGS, with USGS world output said to climb to 294 kt in 2020.",
   "why": "The USGS side summed two world series: mine production and refinery production, each 147 kt in 2020. Compared with mine production alone, the BGS sum agrees within 10% (ratio 1.05). The DR Congo explanation was built on the doubled figure and is withdrawn."
  }
 ]
}