TANZANIA. Tanganyika. Miners at work underground in the Williamson Diamond Mine. The mine was discovered in 1940 by Dr John Thorburn Williamson, from Montfort Quebec, Canada and is possibly one of the richest diamond mines in the world. Williamson found the mine after 6 years of prospecting in the coarse grass and thorn-scrub in Sukumaland. When the true value of the mine was discovered Williamson was offered $5 million for the rites to the land. Instead Williamson preffered to work the mine himself with a small devoted staff. Much of the profits are devoted to the welfare of the employees or is re-invested in the mine. The mine now offers the best living conditions in East Africas for it's 1,500 employees. 1948.