Contamination of ceramic specimens resulting from sample-preparation techniques has the ability to confound efforts of chemical characterization. Primary contamination, identified by significant concentrations of one or more elements, is easily identified. Secondary contamination, resulting from undetected elements influencing detected elements, is more difficult to identify. Evaluation of six powder-extraction techniques identifies variable effects of contamination. Extraction by drilling carries the highest risk of contamination. The grinding of specimens with silicon-carbide wheels may artificially deplete abundances by introducing Si and C. Grinding specimens in an agate mortar and pestle is found to be the technique least likely to result in contamination effects.