The microscopic models which are commonly used to interpret the temperature variations of the centre shifts and quadrupole splittings observed from the Mössbauer spectra of iron-containing minerals are briefly presented and illustrated using the results of recent studies of ortho- and clinopyroxenes. The importance of applied-field Mössbauer spectroscopy for the determination of the electric field gradient is indicated. Aspects of the magnetic spectra of Fe²⁺-bearing minerals emphasise the benefit of using external fields to elucidate the nature of the magnetic ordering. Two Fe³⁺ minerals, bernalite and franklinite, serve as examples to illustrate this point. Finally, two applications of the Mössbauer milliprobe technique are presented: the characterisation of inclusions in diamond, and the determination of the oxidation state of a new iron uranyl sulfate mineral, deliensite.