Comparative marine chemistries of some trivalent metals - Bismuth, rhodium and rare earth elements

The differing marine chemical behaviors of some trivalent elements are compared on the bases of their crustal rock concentrations and of those in various marine compartments. At one extreme, the platinum group element rhodium has a remarkable stability in seawater, perhaps attributable to kinetically hindered complex formation. On the other hand, bismuth is far more reactive as evidenced by its unusual enrichments in ferromanganese minerals and by its depletion in deep waters. The rare earth elements, lanthanum, samarium and lutetium show behaviors intermediate between those of rhodium and bismuth.