Diamonds: Emissions
Mined versus lab-grown: a contested carbon contest
What this tab covers The greenhouse-gas footprint of the commodity at a global level, split by lifecycle phase: extraction (or farming), refining and processing, movement, usage, and recycling or end of life. Intensities are per unit of product; the global total combines intensity with world output. Also covers other environmental impacts and the main levers to cut emissions. Emission intensity 160 kg CO2e per polished carat range 160 for DPA member mines; 511 estimated for lab-grown (contested and highly grid-dependent) · Scope 1 and 2 of mining by Diamond Producers Association members, allocated per polished caratPer polished carat of mined diamond; mine-to-rough (Scope 1 and 2 of mining), not including cutting. Intensity: Trucost (S&P Global) for the Diamond Producers Association, 2019, as reported by JCK. Global total: Derived from Trucost 2019.
Footprint by lifecycle phase
| Phase | Intensity | Share | Main sources of emissions | Notes | Source |
|---|---|---|---|---|---|
| Extraction | most of the 160 kg per polished carat | – | diesel for haul trucks moving hundreds of tonnes of kimberlite per carat; power for crushing | Ore holds less than 1 to about 6 carats per tonne, so energy per carat is high and rises as pits deepen. | Trucost 2019; USGS MCS 2026 (grades) |
| Refining / processing | not in the 160 kg figure; cutting and polishing use mainly electricity | – | crushing, X-ray sorting at the mine; laser sawing and polishing in Surat | Indian cutting runs on a coal-heavy grid, but energy per carat is small next to mining (indicative). | Indicative |
| Movement | negligible per carat | – | air freight of rough and polished | Diamonds are high-value and light, so transport emissions are tiny. | Indicative |
| Usage | none | – | jewellery is worn, not consumed | Not applicable. | Not applicable |
| Recycling / end of life | near zero: resale or recutting | – | estate jewellery resale and recutting | No recycling rate is published; industrial diamond is recovered from used tools (the US recycled about 15 Mct of grit and powder in 2025). | USGS MCS 2026 |
Other environmental impacts
Large open pits and waste dumps, water use in arid Botswana and Namibia, marine seabed disturbance off Namibia, and conflict and labour risks in artisanal alluvial mining. Lab-grown stones made with coal power can exceed mined footprints, but those made with hydro or solar power can be far lower.
Levers to cut emissions
- Renewable power and electrified or trolley-assisted haulage at mines
- Underground mining that moves less waste rock than open pits
- Clean power for Surat cutting and for lab-grown growers in India and China
- Verified provenance and carbon disclosure per stone
India
India cuts about 9 in 10 of the world's diamonds and is a large lab-grown producer, mostly CVD reactors that draw heavily on Gujarat's coal-based grid, which raises the footprint of Indian lab-grown stones unless renewable power is used (indicative).
Emission figures are indicative global averages from the life-cycle studies named; actual footprints vary widely by site, energy mix and method.