Citation: Missen, O. P.; Back, M. E.; Mills, S. J.; Roberts, A. C.; LePage, Y.; Pinch, W. W.; Mandarino, J. A. (2021). Crystal chemistry of zemannite-type structures: III. Keystoneite, the Ni2+-analogue of zemannite, and ferrotellurite discredited. The Canadian Mineralogist, 59, pp. 355-364.