Sources
Statutes and official texts first; secondary sources are labelled as such.
- Hallmarking Act 1973, Schedule 2 (revised text)
- Hallmarking Guidance Notes, British Hallmarking Council and assay offices (Nov. 2022)
- Vienna Convention on precious metals, Technical Decisions Rev. 13 (in force 1 Oct 2026)
- Hallmarking Convention, contracting states
- FTC Jewelry Guides, 16 CFR 23.3 (gold)
- FTC Jewelry Guides, 16 CFR 23.4 (vermeil)
- FTC Jewelry Guides, 16 CFR 23.5 (silver)
- FTC Jewelry Guides, 16 CFR 23.6 (platinum)
- National Gold and Silver Stamping Act, 15 U.S.C. § 294
- 15 U.S.C. § 295 (gold tolerances, 1976 amendment)
- 15 U.S.C. § 296 (silver: sterling and coin)
- 15 U.S.C. § 297 (trademark beside the quality mark, 1961)
- Douane française, table of guarantee marks (2009)
- Poinçon (métal précieux, France), Wikipédia (secondary source)
- Silver Makers' Marks, date-letter tables by assay office
- The Goldsmiths' Company Assay Office, History of hallmarking
- Assay Office Birmingham, timeline
- Sheffield Assay Office, history
- Zolotnik, Wikipedia (secondary source)
- Arithmetic: karats / 24 × 1000 (no external source)
Construction features
- C. Jeanenne Bell, Answers to Questions About Old Jewelry, 1840-1950
- Lang Antiques, Antique Jewelry University (langantiques.com/university)
- Tiffany & Co., Tiffany Setting (1886)
- Van Cleef & Arpels, Serti Mystérieux patent (1933)
- GIA, Gems & Gemology / gia.edu
- Marcel Tolkowsky, Diamond Design (1919)
- Joseph Asscher, 1902 patent
- Henry Grossbard, 1977 patent
- Charles Goodyear, vulcanization patent (1844)
- John W. Hyatt, celluloid patent (1869)
- Leo Baekeland, 1907 patent
- Auguste Verneuil (1902)
- Swarovski y Christian Dior (1955)