Algorithms for quantification by SEM/EDS always specify that the material being analyzed should be homogeneous. Every instruction on analysis by SEM/EDS warns against analyzing heterogeneous samples. However, in day-to-day analysis, it is extremely common to encounter samples which are heterogeneous and these samples must be analyzed. It is very common for an analyst to simply scan an entire field of view in the SEM, acquire an x-ray spectrum from this field of view, press the button for standardless quantification, and hope for the best. This work explores the magnitude of this problem and characterizes it with measurements. A solution is then proposed for performing this kind of analysis. The results of analyses of multiple areas showed larger variations than the variation between the area-weighted and gross spectrum calculations. The results obtained were consistent with the nominal bulk concentrations for homogeneous materials.