What is the type of mineral mined at Johannesburg in South Africa?

Johannesburg, South Africa is famous for its rich gold deposits. The city is located on the Witwatersrand Basin, which is one of the world's largest sources of gold. Gold mining has been the primary economic driver of Johannesburg since its establishment in the late 19th century. The gold found in Johannesburg is primarily in the form of gold-bearing reefs, which are layers of rock that contain gold deposits. The gold is extracted through underground mining operations, and the city has a long history of deep-level mining. Johannesburg's gold mining industry has played a significant role in shaping the city's economy, society, and infrastructure, making it one of the most important gold-mining regions in the world.