Opencast workings are shown in this picture of the Venetia diamond mine, in Limpopo province, in the north-east corner of South Africa. Diamond mining company De Beers, an Anglo American group company, is currently undertaking a sizeable venture to convert Venetia from an opencast mine, which produces about four-million carats a year, into an underground mine. De Beers is investing R20-billion in the conversion, which will begin producing diamonds in 2021 and ramp up to full production in 2024. Mining will continue underground to well beyond 2040.