and thus readily dissolve to release Fe 2+ ions to the surrounding environment. Fe(II)-minerals are only stable at neutral or alkaline pH in anoxic environments (i.e., when no oxygen is present).

Dilute solutions of Fe(NCS)2+ have their equilibrium positions shifted with the addition of Fe(NO3)3, KSCN, NaOH, and AgNO3. The ferric thiocyanate solution is blood red in color, and the intensity of ...