✨ Metallurgy & CraftUpdated: September 2, 2026
Historical Precious Metal Hallmarks: London Assay Office, French Eagle Heads & Platinum Stamps
Curated by Royal Adornments & Historical Gemology Curatorial Board
Deciphering gold and platinum stamps: medieval London Goldsmiths' Hall hallmarks, French state guarantee eagle heads, and Austrian Dianakopf marks.
Hallmarks represent the oldest continuous form of consumer protection in history, established by King Edward I in 1300 at Goldsmiths' Hall in London.
1. Major Historical Hallmark Systems
| Country / Assay Authority | Standard Mark Symbol | Precious Metal & Fineness | Historical Era |
|---|---|---|---|
| Great Britain (London) | Leopard's Head + Lion Passant | Sterling Silver (.925) / 18K Gold (.750) | 1300 to Present |
| France (Garantie) | Eagle's Head (Tête d'Aigle) | 18K Gold (.750 fineness) | 1838 to Present |
| France (Platinum) | Dog's Head (Tête de Chien) | 950 Platinum (.950 fineness) | 1912 to Present |
| Austria-Hungary | Diana Head (Dianakopf) | Silver (800 / 900 fineness) + City Letter | 1867 to 1922 |
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Royal Adornments & Historical Gemology Curatorial Board
Our curatorial panel researches historical royal provenance, antique lapidary cuts, precious metal hallmarking archives, and scientific gemological origins.
Researching Antique Jewelry Provenance?
Consult our historical hallmark archives, period maker records, and gemological monograph collection.