A colorimetric test was developed to detect the presence of asbestos (1332214) in bulk samples by the formation of color complexes from added magnesium (II) (Mg) and iron (II) (Fe). In the magnesium test, several drops of Mg reagent are added directly to the sample, which is washed with glycerine and mixed with phosphoric acid and sodium hydroxide. A blue color indicates that chrysotile (12001295) may be present. In the iron test, several drops of Fe reagent are added to the sample, which is washed with an acetic and sulfuric acid mixture. Each acid then is added separately, and hydrofluoric acid also is added. A red color indicates the possible presence of amosite (12172735) or crocidolite (12001284). If both tests give a negative response, the probability is low that asbestos is present. If the presence of Mg or Fe is indicated, further analysis to confirm, identify, and quantitate the asbestos is required.