The brittleness of a mineral and its scattering upon crushing cannot be anticipated, so the optimal method of preparation of an unknown mineral for analysis with diamond attenuated total reflection (D-ATR) is by mounting the sample in an immersion oil. The advantage of D-ATR analysis is that the sample preparation is minimal and requires no additional preparation beyond that for traditional polarized light microscopy. Once the sample is prepared, the time required for infrared microprobe analysis is approximately 1 minute for each mineral grain. The disadvantage encountered in this study was the inability to easily identify certain types of minerals, such as halide minerals, metal oxide, and sulfide minerals, as well as minerals with refractive indexes greater than that of the diamond. In addition, there were several minerals with infrared spectra that were indistinguishable. Although a definite identification of a mineral by its infrared spectrum alone is not always achievable, the data can be used to narrow the mineral possibilities. When paired with polarized light microscopy in order to observe optical and morphological properties, a definitive identification is usually achieved. Ninety-six different mineral varieties were analyzed in this study. The descriptions of materials and methods address instrumentation, mineral samples, test procedure, method of infrared microprobe analysis, spectral processing, mineral library database analysis, and single blind study. 6 figures and 21 references