Diamonds: Trading
Sights, tenders and the road from Antwerp to Mumbai
What this tab covers How and where it is bought and sold: who buys and sells, exchanges and benchmarks, contract types, the big trading houses and how prices are discovered.Diamonds have no exchange and no standard contract, because every stone differs. Miners sell rough through sights to approved buyers, as De Beers does, through tenders and auctions, or through state-linked sellers such as Russia's Alrosa. Rough then passes through trading centres such as Antwerp, Dubai, Tel Aviv and Mumbai to cutters, mostly in India. Polished prices are referenced to dealer price lists and grading by colour, clarity, cut and carat. Industrial diamond is a cheap commodity by contrast: US imports of grit and powder averaged 19 cents per carat in 2024.
Where it is bought (buyers)
- Indian manufacturers in Surat and Mumbai buy most of the world's rough at sights, tenders and auctions
- Polished buyers are jewellery makers and retailers in the US, China, India and the Middle East, buying through bourses and on memo
- Industrial users (saw, bit and wheel makers) buy synthetic grit, mainly from China (77% of US grit and powder imports in 2021-24, USGS)
Where it is sold (sellers)
- De Beers sells rough from Botswana, Namibia, South Africa and Canada at sights in Gaborone; it held three sights in Q4 2025 selling 5.9 Mct for $571 million
- Alrosa sells Russian rough, now barred from G7 and EU markets
- Rio Tinto, Angolan and other producers sell by tender and auction, often in Antwerp and Dubai
- India, Hong Kong, Belgium and Israel re-export polished stones (top HS 7102 exporters by value in 2024, Comtrade)
Exchanges and benchmarks
| Venue | Contract | Notes |
|---|---|---|
| No futures market | No LME, CME or MCX diamond contract | Prices are set bilaterally; bourses are trading floors, not price-setting exchanges |
| Bharat Diamond Bourse (Mumbai) and Surat Diamond Bourse | Physical trading floors | India's main centres for rough and polished dealing |
| Antwerp, Dubai, Ramat Gan and Hong Kong bourses | Physical trading floors | Rough tenders and polished trade |
Contract types
- Sight contracts: sightholders commit to buy boxes of rough at prices set by the producer
- Tenders and auctions for rough, especially large or special stones
- Polished sold on memo (consignment) to retailers and priced as a discount to a list price
- Kimberley Process certificates on every rough shipment; G7 traceability rules for stones over set sizes
Top trading houses
- No large commodity trading houses; trade runs through sightholders, dealers and bourse members
- Leading Indian sightholders and manufacturers (for example Kiran Gems, Hari Krishna Exports)
How prices are discovered
- De Beers price index and sight prices (reported in Anglo American results)
- Rapaport polished price list and RapNet trading data
- Zimnisky Global Rough Diamond Price Index
- Tender results published by producers