Mbuji-Mayi

Diamonds were found in the gravels of the Kasaï rivers early in the twentieth century, and the deposits around the Mbuji-Mayi river proved to be among the richest sources of industrial stones in the world. A mining settlement grew at Bakwanga to work them, run by a company whose successor, the Société minière de Bakwanga, known as MIBA, became the city's reason for existing. The town was built by and for the mine: workers' camps, company installations and the tracks that carried stones and supplies.

Independence turned it into a political centre. In 1960 Albert Kalonji declared the secession of South Kasai with its capital at Bakwanga, and tens of thousands of Luba who had left the region returned or were driven there amid fighting between Luba and Lulua communities and an army offensive that killed great numbers before the state was reabsorbed in 1962. The town took the name Mbuji-Mayi at the end of 1962.

Under Mobutu the diamond trade kept the city going as the rest of the economy collapsed, and when the state currency failed the stones served in its place. The population swelled with people from across the Kasaï, and the built-up area spread far beyond anything the roads, water mains and power lines could serve. MIBA's industrial output has fallen a long way from its peak, and most stones are now dug by hand by artisanal miners and sold to licensed buying houses in town — a shift that has left the city large, busy and poorly served, and dependent on trade rather than on a single company.

Mbuji-Mayi is the great city of the Luba-Kasai, and Tshiluba is heard everywhere, with French kept for offices and classrooms and Lingala arriving with music and soldiers from the capital. Kasaïans have a national reputation for schooling, commerce and political argument, and the ties between this city and the Luba communities of Kinshasa and Lubumbashi are constant, carried by traders, students and remittances.

Customary authority runs alongside the administration. Chiefs and family elders are consulted on land, marriage and disputes, extended families share the cost of school fees and funerals, and a funeral can occupy a street for days. Respect for age is expected, greetings are lengthy, and refusals are made indirectly.

Church life is loud and central: Catholic and Protestant missions of long standing, Kimbanguist congregations and a very large number of revival churches whose choirs rehearse in courtyards through the evening. Music follows two strands — mutuashi, the Luba dance rhythm carried to national fame by the singer Tshala Muana, and the rumba and ndombolo that dominate the bars. Diamonds colour social life as well as the economy: fortunes are made and lost quickly, wealth is displayed, and the trade is discussed with a mixture of pride and suspicion.

Estimates of the population vary widely in the absence of a recent census: about 1,480,000 by one 2010 estimate and as many as 3,500,000 by a United Nations figure for 2008, which leaves Mbuji-Mayi generally counted the second largest city in the country after Kinshasa. The built-up area covers a great deal of ground in low compounds of brick and sheet metal, with cultivation and mining pits at its edges.

The economy turns on diamonds and on the trade that follows them: digging, sorting, buying, transport and the shops and services the money supports, along with farming on the outskirts. Formal employment is scarce, and much of the city lives on small trade and family networks. Electricity supply is poor even by Congolese standards and generators are common, water comes from standpipes and wells, and the road and rail links that bring in fuel, cement and flour are slow, which keeps prices high.

The day begins before dawn in the markets and ends early outside the bars, with motorbike taxis running all day on unpaved streets. Conversation turns on the price of maize flour and fuel, the exchange rate, school fees, the state of the mines and the fortunes of the diggers, and on the weather in a place where a heavy storm can make half the streets impassable.

Bidia is the foundation of the meal: a stiff dough of maize and cassava flour, rolled in the right hand and dipped into a sauce. Pondu, cassava leaves pounded and simmered with palm oil and onion, is the standard green, and sauces are built on groundnuts, palm oil, okra, aubergine and pili-pili chilli. Beans, sweet potatoes and rice fill out the plate.

Meat matters more here than fish, which arrives dried or smoked from the rivers rather than fresh: goat and chicken for guests and celebrations, skewered meat grilled over charcoal in the evening. Caterpillars gathered in season are fried with onion and sold by the cup, a delicacy that outsiders find surprising and locals do not. Groundnuts, maize and cassava from the surrounding farmland fill the markets, along with mangoes, bananas, avocados and pineapples in season.

Eating out means small kitchens serving bidia and sauce, or the braziers set up beside bars at nightfall. Bottled lager comes in by road and rail from Kinshasa and Lubumbashi and is drunk cold and in large bottles; palm wine and home-brewed maize or sorghum beer are the traditional drinks, and a strong home-distilled spirit circulates informally. Sugary tea or instant coffee with bread or fried dough starts the day.