There are many techniques available to make site-specific quantitative chemical analyses of tinysamples, i.e., samples on the order of 1 - 10s of micrometres (which may themselves contain eventinier heterogeneities). Specifically, we are considering the analysis of the products of diamondanvil cell (DAC) experiments, although the limitations will be much the same for any other tiny,heterogeneous geologically-relevant sample. Measurements of larger samples such as thin sectionsmay also occasionally require a high spatial resolution for detailed microtextural examination. Webegin by listing and briefly describing many techniques that can, and have, been used for examiningsuch samples. Following this, the case of using EPMA for tiny samples is examined in more detailby quantifying the effects of sample thickness and secondary fluorescence using both simulationsand measurements of synthetic samples. Quenched molten metal from DAC experiments oftencontains a sub-μm exsolution texture: we explore the composition of the exsolved phase and thenature of the interface with the matrix by atom probe tomography (APT), and discuss itsimplications for ‘large’ spot EPMA measurements of these quenched metals.
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