Here are the leading jewellery companies and groups worldwide (ranked roughly by size, sales and market influence), with a short note for each and sources for the biggest claims.

1. Richemont — owner of Cartier, Van Cleef & Arpels, Buccellati and others; jewellery is the largest part of the group and drove strong recent sales. (ft.com)

2. LVMH (Watches & Jewelry) — owns Bulgari, Tiffany & Co., Chaumet, Fred and others; a top luxury jewellery/watches division by revenue and brand influence. (en.wikipedia.org)

3. Chow Tai Fook Jewellery Group — one of the world’s largest jewellery retailers/manufacturers by revenue, with a huge retail footprint in Greater China and strong annual sales. (accesswire.com)

4. Pandora A/S — global mass-market jewellery maker/retailer (charms/consumer jewellery); very large revenues and an extensive retail network. (en.wikipedia.org)

5. Signet Jewelers — the largest jewellery retailer in the US (brands include Kay, Zales, Jared) and a major global retail player. (investors.com)

6. The Swatch Group (includes Harry Winston among its brands) — large Swiss group with both watch and jewellery businesses; owns notable luxury jewellery/watch houses. (en.wikipedia.org)

7. Chow Sang Sang / Lukfook / Sokolov (regional heavyweights) — major publicly listed jewellery groups in Greater China and Russia that rank among the biggest by store count and production. (en.wikipedia.org)

8. De Beers (and scattered diamond specialists such as Graff, Graff/Chopard as private houses) — dominant players in diamonds/high-jewellery, influential across supply chain and luxury markets. (industry summaries and brand lists referenced above). (ft.com)

Notes and context

• The jewellery market splits into: (a) large luxury conglomerates (Richemont, LVMH, Swatch) that own high-jewellery maisons; (b) big retail/manufacturer groups (Chow Tai Fook, Pandora, Signet) focused on mass/luxury retail; and (c) specialist diamond and haute-joaillerie houses. The ranking above mixes revenue/scale with brand influence. (ft.com)
• If you want a strict ranking by a single metric (e.g., annual revenue, market cap, number of stores or luxury brand valuation), tell me which metric you prefer and I’ll produce a ranked list with up-to-date figures and sources.