Indeed, not a whole emerald mine, the same source:

We located reporting from as far back as 2009 and 2014 that said when Elon Musk (“Elon” hereafter) was a child in South Africa in the 1980s, his father (“Errol” hereafter) at some point owned “a stake in an emerald mine” near Lake Tanganyika in Zambia, not South Africa.