How to Date Antique Jewellery: The Earliest-Date Register

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Date by the latest feature, not the oldest look

An antique piece can be no older than its newest original feature. Style can be copied at any time, but a mark, a material or a fitting cannot appear before it existed.

Our ruby and diamond half hoop ring, MFA-J26-135, shows why. It has every Victorian feature: three rubies divided by pairs of small diamonds, a carved scroll gallery and a slim tapering shank. Our Victorian jewellery guide shows the originals it follows.

Inside the shank the hallmark reads S&D, a crown, 750, the Birmingham anchor and a date letter. The crown with 750 is the British gold standard mark set by the Hallmarking Act 1973, which came into force in 1975. Before 1975, 18 carat gold was marked with a crown and 18. So the ring was hallmarked in 1975 or later, whatever its style says.

It is a well made later ring in the Victorian manner, and our listing describes it as an 18KT gold half hoop, hallmarked, with no Victorian date. The same test works on any hallmarked British gold: our gold hallmarks guide decodes every mark.

What we look for when a piece arrives

• The hallmark or stamp. Standard mark, town mark, date letter and sponsor, read with a loupe.
• The stones. Cut, natural or synthetic, and whether they are original to the mount.
• The construction. Hand-made or cast, solder repairs, replaced shanks and later fittings.
• The fittings. Clasps, catches, hinges and earring backs, each with its own start date.
• The wear. Even, honest wear in the places that touch skin and clothing.

Sources: Hallmarking Act 1973, Schedule 2; Assay Office London.

The earliest-date register

The register lists 80 marks, materials, cuts and fittings with the earliest year each one can appear and, where it ended, the last. Find every feature on your piece, then take the latest start date: the piece cannot be older than that.

Each row links its own source: the assay offices, the Hallmarking Act 1973, The National Archives, GIA, patents and museum or specialist references. A start date is the earliest a feature can appear, not proof that a piece was made then.

The register as a timeline

1. 1784The duty mark (sovereign's head) begins. It ends in 1890.
2. 18549, 12 and 15 carat gold become legal British standards.
3. 1902Verneuil announces jewellery-sized synthetic rubies.
4. 1919Tolkowsky publishes the modern round brilliant proportions.
5. 193215 and 12 carat end; 14 carat begins.
6. 1975Crown with 375, 585, 750 or 916 on gold; platinum hallmarked; one date letter for all offices.
7. 1976Cubic zirconia goes into commercial production.
8. 1998Synthetic moissanite reaches the jewellery market.
9. 1999925 compulsory on silver; the lion and the date letter become optional.
10. 2010Palladium hallmarking compulsory.

Sources: each row links its own source. Compiled by Mozeris Fine Antiques, October 2026. Corrections are welcome through our contact page.

Marks that date a piece

British hallmarks are the most precise dating evidence on jewellery, because the law fixed each mark's dates. Read the standard mark first, then the town mark and the date letter.

• Carat in figures and decimals. 15 .625, 12 .5 and 9 .375 began in 1854. 15 and 12 ended in 1932, when 14 .585 began.
• Crown with a three-figure number. 375, 585, 750 or 916 beside a crown means 1975 or later. Before 1975 the crown sat beside 18 or 22, and the lower carats had no crown.
• Platinum and palladium. The orb hallmark starts in 1975 and the Pallas Athene head in 2009, compulsory from 2010. See our platinum hallmarks guide.
• The date letter. From 1975 every office shares one letter, changing on 1 January. From 1999 the date letter is optional.
• Town marks that stopped. York, Exeter, Newcastle, Chester and Glasgow closed, so their marks set a latest date. Our assay offices guide covers each office.

A stamp is not a hallmark. 18CT and PLAT stamped by a maker tell you the metals but give no town and no year. Our guide to hallmarks and maker's marks explains the difference, and how to identify fake gold jewellery covers stamps that lie.

Foreign marks have their own dates: the French eagle's head for 18 carat gold from 1838, the Russian kokoshnik from 1899, and US karat stamps under federal law from 1906.

Sources: Hallmarking Act 1973, Schedule 2; Assay Office London; Birmingham Assay Office; Assay Office London, UK hallmarks; Adin, eagle's head hallmark; silvercollection.it, kokoshnik; 15 U.S.C. chapter 8 (Act of 13 June 1906).

Materials and stones that date a piece

Synthetic stones, imitations and modern treatments each have a first year. One synthetic or treated stone in an original setting dates the whole piece to that year or later.

• Synthetic ruby and sapphire. Flame-fusion ruby from 1902 and blue sapphire from 1911. Under a loupe they show curved growth lines where natural stones show straight ones.
• Diamond imitations. Synthetic rutile from the late 1940s, strontium titanate from the 1950s, YAG and GGG from the 1960s, cubic zirconia from 1976 and moissanite from 1998.
• Cultured pearls. Mikimoto produced hemispherical cultured pearls in 1893 and round ones in 1905. Our natural and cultured pearls guide and Mikimoto guide explain how to tell them apart.
• White gold and platinum. Platinum jewellery from about 1900, white gold from 1913. Our guide is my ring platinum or white gold shows how to tell the two apart.
• New stones. Demantoid from 1868, black opal from 1903, tanzanite and tsavorite from 1967 and Paraiba tourmaline from 1989.
• Plastics. Celluloid from 1870, Bakelite from 1907 and Lucite from 1937.

A replaced stone dates only the repair. If one stone differs from the rest, the setting around it often shows the work.

Sources: Lang Antiques, synthetic corundum; GIA, simulants; Wikipedia, Cubic zirconia; Wikipedia, Moissanite; GIA, Japanese cultured pearls; Johnson Matthey Technology Review; Navette Jewellery, white gold; GIA, tanzanite; Wikipedia, Bakelite.

Clasps, catches and fittings

Fittings date a piece as well as marks do, as long as they are original. A clasp or earring back is the part most often replaced, so check that its metal, colour and wear match the rest. Screw fittings in particular were often added later to older earrings.

• Brooch pins. The trombone catch from the mid-1850s; patented safety attachments from 1891.
• Necklace clasps. The bolt ring from the 1840s, and the spring ring with a bale from about 1900.
• Earrings. Screw-back fittings were patented in 1894 and became common from the 1910s. The post and butterfly back belongs to the 1920s onwards and the omega back to the 1960s onwards.

Our guides to identifying antique and vintage necklace clasps and dating earrings by their fastenings show each type close up.

Sources: Navette Jewellery, the safety pin; US patent 460,296 (1891); Navette Jewellery, clasps; Navette Jewellery, earring patents.

Diamond cuts at a glance

The cut of a diamond places it in a period, but recutting and resetting are common, so the cut dates the stone rather than the mount.

• Rose cut. A flat base and a dome of triangular facets. See rose cut diamond rings.
• Old mine cut. A cushion outline, high crown and open culet. See the old mine cut guide.
• Old European cut. A round outline, made practical by the bruting machine of 1874. See the old European cut guide.
• Modern round brilliant. Proportions published by Tolkowsky in 1919. A large table and a pointed culet point to the 20th century.
• Asscher cut. From 1902.

Our rose cut ring above shows why each part is dated separately: the Georgian diamond sits on a 15KT shank, and 15 carat gold was a British standard only from 1854 to 1932.

Sources: Lang Antiques, brilliant cut; Wikipedia, Marcel Tolkowsky; Wikipedia, Asscher cut; Assay Office London.

Victorian-style or Victorian? Seven tells of a reproduction

A reproduction is given away by one feature that did not exist in the period it copies. These seven are the ones we meet most often.

1. A number inside a British gold hallmarkCrown with 375, 585 or 750 means 1975 or later, as on our ruby half hoop.
2. 14 carat in a British hallmark14ct was not a British standard until 1932.
3. A British platinum hallmarkThe orb starts in 1975.
4. Cubic zirconia or moissaniteFrom 1976 and 1998.
5. A synthetic ruby or sapphireFrom 1902 and 1911; look for curved growth lines.
6. Modern brilliant proportionsA large table and a pointed culet follow Tolkowsky's 1919 proportions; old cuts have a small table and an open culet.
7. A post and butterfly earring backFrom the 1920s, on earrings sold as Victorian.

One tell can be a later repair. Two or three together usually settle it. Reproductions are not fakes when they are sold as what they are: our note on Art Deco jewellery reproductions shows the same reasoning for the 1920s.

Sources: Hallmarking Act 1973, Schedule 2; Birmingham Assay Office; Wikipedia, Cubic zirconia; Wikipedia, Moissanite; Lang Antiques, synthetic corundum; Wikipedia, Marcel Tolkowsky; Navette Jewellery, earring patents.

When to get a second opinion

When the marks are worn, the stones are untested or the parts disagree, a specialist can date the piece in hand. Every piece is different, so we value each one individually.

• Period and originality. A piece that is all of one date, with its original stones and fittings.
• Metal and marks. Hallmarked gold and platinum, and a readable maker's mark.
• Stones. Natural stones and their cut.
• Maker. A known jeweller or a signed piece.
• Condition. Worn shanks, repairs and replaced parts.
• Provenance. Boxes, receipts and family history.

Send us a few photos and we will tell you what yours is worth, free and with no obligation.

We buy antique jewellery every week: see sell your antique jewellery, sell your Victorian jewellery and sell your gold jewellery. If the piece came to you with other jewellery, read inherited jewellery: what to do, and see how we authenticate antique jewellery.

Frequently asked questions

Related guides

• Gold hallmarks and stamps decodedEvery British and foreign gold mark.
• Platinum hallmarks explainedThe orb, 950 and the other standards.
• Assay offices guideTown marks, open and closed.
• Old European cut diamondsThe cut of the late 19th and early 20th century.
• Victorian jewelleryStyles and makers, 1837 to 1901.
• How we authenticate antique jewelleryWhat we check, and why.