De Beers and Botswana’s government have signed a ten-year deal to jointly fund a marketing campaign to boost demand for natural diamonds. The partnership, which also covers diamond sales and mining licenses, aims to counter declining demand, particularly from China, and address the impact of lab-grown diamonds on the market. For Botswana, which owns 15% of De Beers and depends on diamonds for about a third of budget revenues, it has led to a significant widening of its fiscal deficit.