Grains of platinum group minerals panned from the farm Maandagshoek in the eastern Bushveld Complex, where the Merensky Reef was found in 1924. These photographs were reported by Oberthür et al. (11), and are reproduced here by permission of the Editor of The Canadian Mineralogist. Note the scale, indicating that these are large grains (by platinum group mineral standards), and are very different from anything found in chromitite layers.

Fig. 2(a) Grain (a) is a well-rounded grain of platinum-iron alloy; its shape suggests that it has been transported over a long distance and rolled about in a river system