[
  {
    "id": "london",
    "name": "London Assay Office",
    "operator": "The Goldsmiths' Company",
    "country": "GB",
    "city": "London",
    "symbol": "LEOPARDS_HEAD",
    "symbol_description": "Leopard's head (crowned 1478-1821, uncrowned thereafter)",
    "founded": 1300,
    "closed": null,
    "active": true,
    "address": "Goldsmiths' Hall, Foster Lane, London EC2V 6BN",
    "website": "https://www.assayofficelondon.co.uk/",
    "wikidata_qid": "Q5586057",
    "notes": "Oldest assay office in continuous operation in the UK. Established under royal charter 1300. The leopard's head is among the oldest hallmarks in continuous use globally.",
    "sources": ["Goldsmiths' Company historical records"]
  },
  {
    "id": "birmingham",
    "name": "Birmingham Assay Office",
    "operator": "The Assay Office Birmingham",
    "country": "GB",
    "city": "Birmingham",
    "symbol": "ANCHOR",
    "symbol_description": "Anchor",
    "founded": 1773,
    "closed": null,
    "active": true,
    "address": "1 Moreton Street, Birmingham B1 3AX",
    "website": "https://theassayoffice.co.uk/",
    "wikidata_qid": "Q4866015",
    "notes": "Established by Act of Parliament 1773 alongside Sheffield, lobbied by Matthew Boulton. Historically the largest UK assay office by volume.",
    "sources": ["Birmingham Assay Office Act 1773"]
  },
  {
    "id": "sheffield",
    "name": "Sheffield Assay Office",
    "operator": "The Sheffield Assay Office",
    "country": "GB",
    "city": "Sheffield",
    "symbol": "ROSE",
    "symbol_description": "Tudor rose (since 1975 for both gold and silver; previously a crown for gold)",
    "founded": 1773,
    "closed": null,
    "active": true,
    "address": "Beulah Road, Hillsborough, Sheffield S6 2AN",
    "website": "https://www.assayoffice.co.uk/",
    "wikidata_qid": "Q7493316",
    "notes": "Established by same 1773 Act as Birmingham. Historically focused on silver (Sheffield silversmithing tradition). Changed gold mark from crown to rose in 1975.",
    "sources": ["Birmingham Assay Office Act 1773"]
  },
  {
    "id": "edinburgh",
    "name": "Edinburgh Assay Office",
    "operator": "The Edinburgh Assay Office",
    "country": "GB",
    "city": "Edinburgh",
    "symbol": "CASTLE",
    "symbol_description": "Three-towered castle",
    "founded": 1457,
    "closed": null,
    "active": true,
    "address": "Goldsmiths' Hall, 24 Broughton Street, Edinburgh EH1 3RH",
    "website": "https://www.edinburghassayoffice.co.uk/",
    "wikidata_qid": "Q5337797",
    "notes": "Scottish assay office, operates under separate Scottish hallmarking tradition (with the lion rampant historically used as standard mark for sterling).",
    "sources": ["Edinburgh Assay Office historical records"]
  },
  {
    "id": "chester",
    "name": "Chester Assay Office",
    "operator": "Chester Assay Office (closed)",
    "country": "GB",
    "city": "Chester",
    "symbol": "THREE_WHEATSHEAVES",
    "symbol_description": "Three wheatsheaves (sometimes with sword)",
    "founded": 1701,
    "closed": 1962,
    "active": false,
    "wikidata_qid": "Q5092572",
    "notes": "Operated 1701-1962. The Chester mark is a useful temporal anchor for dating English jewelry to before 1962. Records transferred to Birmingham upon closure.",
    "sources": ["Chester Assay Office historical records"]
  },
  {
    "id": "newcastle",
    "name": "Newcastle Assay Office",
    "operator": "Newcastle Assay Office (closed)",
    "country": "GB",
    "city": "Newcastle upon Tyne",
    "symbol": "THREE_CASTLES",
    "symbol_description": "Three castles",
    "founded": 1702,
    "closed": 1884,
    "active": false,
    "wikidata_qid": null,
    "notes": "Operated 1702-1884. Earlier guild-based assay history dating to the 14th century. Three-castles mark distinguishes from Edinburgh's single castle.",
    "sources": []
  },
  {
    "id": "york",
    "name": "York Assay Office",
    "operator": "York Assay Office (closed)",
    "country": "GB",
    "city": "York",
    "symbol": "FIVE_LIONS",
    "symbol_description": "Cross with five lions passant",
    "founded": 1560,
    "closed": 1858,
    "active": false,
    "wikidata_qid": null,
    "notes": "One of the earliest provincial English assay offices. Closed 1858. Pieces with York marks date pre-1858.",
    "sources": []
  },
  {
    "id": "exeter",
    "name": "Exeter Assay Office",
    "operator": "Exeter Assay Office (closed)",
    "country": "GB",
    "city": "Exeter",
    "symbol": "X_CROWNED",
    "symbol_description": "Letter X (crowned)",
    "founded": 1701,
    "closed": 1883,
    "active": false,
    "wikidata_qid": null,
    "notes": "Operated 1701-1883. West Country English jewelry with this mark dates to pre-1883.",
    "sources": []
  },
  {
    "id": "dublin",
    "name": "Dublin Assay Office",
    "operator": "The Assay Office Dublin",
    "country": "IE",
    "city": "Dublin",
    "symbol": "HARP_CROWNED",
    "symbol_description": "Crowned harp (Hibernia figure added in 1731 as duty mark, retained as office mark)",
    "founded": 1637,
    "closed": null,
    "active": true,
    "address": "Dublin Castle, Dublin 2",
    "website": "https://www.assay.ie/",
    "wikidata_qid": "Q3611213",
    "notes": "Oldest active assay office on the island of Ireland. The Hibernia figure was added in 1731 as a duty-paid mark and retained as a secondary office mark.",
    "sources": []
  },
  {
    "id": "paris",
    "name": "Paris Assay Office (Garantie)",
    "operator": "Direction Générale des Douanes et Droits Indirects",
    "country": "FR",
    "city": "Paris",
    "symbol": "MINERVA_HEAD",
    "symbol_description": "Minerva head (silver, 1st standard 950); eagle head for gold (1st standard 750); horse head (2nd standard); rhinoceros (3rd)",
    "founded": 1275,
    "closed": null,
    "active": true,
    "website": "https://www.douane.gouv.fr/",
    "wikidata_qid": null,
    "notes": "French national hallmarking system administered by Customs (Direction Générale des Douanes). Symbols: eagle head = 750 gold, owl = imports, Minerva head = 950 silver. Numeric within symbol = standard number.",
    "sources": ["French Code Général des Impôts"]
  },
  {
    "id": "vicenza",
    "name": "Vicenza Assay Office",
    "operator": "Camera di Commercio di Vicenza",
    "country": "IT",
    "city": "Vicenza",
    "symbol": "VI",
    "symbol_description": "Province code VI within rectangle",
    "founded": null,
    "closed": null,
    "active": true,
    "wikidata_qid": null,
    "notes": "Italian hallmarking is by province; each piece carries a province code (e.g., VI for Vicenza, AR for Arezzo, MI for Milan) plus fineness number and maker's identifier.",
    "sources": ["Italian Decreto Legislativo 251/1999"]
  },
  {
    "id": "stockholm",
    "name": "Stockholm — Swedish Assay System",
    "operator": "Swedac",
    "country": "SE",
    "city": "Stockholm",
    "symbol": "TRIPLE_CROWN",
    "symbol_description": "Three crowns (Tre Kronor) — historical Swedish hallmark",
    "founded": 1485,
    "closed": null,
    "active": true,
    "website": "https://www.swedac.se/",
    "wikidata_qid": null,
    "notes": "Swedish hallmarking dates to medieval guild marks. Modern system uses CCM (Vienna Convention) marks plus the three-crowns 'Tre Kronor' national mark. Sweden signed Vienna Convention 1972.",
    "sources": ["Vienna Convention on Control of Articles of Precious Metals"]
  },
  {
    "id": "japan_mint",
    "name": "Japan Mint (Zōheikyoku) Hallmark",
    "operator": "Japan Mint (造幣局, Zōheikyoku)",
    "country": "JP",
    "city": "Osaka",
    "symbol": "JIS_HALLMARK",
    "symbol_description": "Chrysanthemum and balance/scale",
    "founded": 1929,
    "closed": null,
    "active": true,
    "website": "https://www.mint.go.jp/eng/",
    "wikidata_qid": "Q1148671",
    "notes": "Japanese national hallmark system. Optional but prestigious. Operated by the Japan Mint (Independent Administrative Institution). Mark issued after independent assay verification of stamped purity.",
    "sources": ["Japan Mint public records"]
  },
  {
    "id": "bis_india",
    "name": "BIS Hallmarking — India",
    "operator": "Bureau of Indian Standards",
    "country": "IN",
    "city": "New Delhi",
    "symbol": "BIS_HALLMARK",
    "symbol_description": "BIS logo + fineness + jeweler ID + HUID code (6 alphanumeric)",
    "founded": 2000,
    "closed": null,
    "active": true,
    "website": "https://www.bis.gov.in/",
    "wikidata_qid": "Q866935",
    "notes": "Indian national hallmarking system. Voluntary 2000-2021; mandatory for gold since June 2021 with the introduction of HUID (Hallmark Unique Identification) traceability codes. Each piece carries a 6-digit alphanumeric HUID.",
    "sources": ["Bureau of Indian Standards IS 1417"]
  },
  {
    "id": "dubai_central_lab",
    "name": "Dubai Central Laboratory",
    "operator": "Dubai Municipality",
    "country": "AE",
    "city": "Dubai",
    "symbol": null,
    "symbol_description": "DCL stamp with fineness",
    "founded": 1996,
    "closed": null,
    "active": true,
    "website": "https://www.dm.gov.ae/",
    "wikidata_qid": null,
    "notes": "UAE national assay authority. Required hallmarking for all jewelry sold in Dubai. Recognized by the GCC. Common standards: 916 (22K), 875 (21K), 750 (18K).",
    "sources": []
  }
]