[1] In 1904 he came to South Africa on study leave, but soon resigned from the German civil service to start his own geology and mining engineering consulting practice.

Even though Merensky's consulting work was a financial success, he started trading speculatively on the stock market, not just for his own account, but also for local and German friends and family.

The next decade, his 40s, would prove to be extremely challenging for him, starting with World War I (1914–1918), which, due to his Prussian Army background, he spent in a concentration camp near Pietermaritzburg.

He also became seriously ill during his internment, and it took some time after his release in 1919 to recuperate, but the post-war depression and the destruction of the German economy meant that mining consulting work was scarce and he still had loads of debt from his speculative trading days.

[9] By early September 1924 they had discovered the famous Merensky Reef, tracing it over many kilometers whilst procuring the necessary surface area mining rights and options for the L.P.

Despite the reef extending some 300 kilometeres and being the largest discovered platinum deposit in the world, Merensky made just enough money to settle his debts – and pay for a well-deserved holiday in Germany in 1926.

As De Beers' Sir Ernest Oppenheimer quipped, "You won't often meet a man who comes in with sixpence in his pocket and leaves with a million pounds.

First he purchased the Westfalia estate near Duiwelskloof from Sir Lionel Phillips, the mining magnate and politician, adding adjacent farms until the total area constituted more than 5,000 hectares.

In 1937 he exercised one such option, buying the farm Jagdlust 418 K.S., 80 kilometers southest of Pietersburg, where an extremely rich seam of chrome oxide was discovered and developed.

That same year he also heard from an acquaintance, Max Rhu, that an old prospector had come across an extensive deposit of high quality vermiculite near Phalaborwa, which Merensky then developed into one of the largest and richest in the world and mining it with his Transvaal Ore Company.