Band I center vs. BAR diagram from M. J. Gaffey et al. (1993) for the two-subgroup analysis. The polygonal region corresponds to the S(IV) subtype associated with ordinary chondrites (OC). The horizontal lines represent the approximate boundaries for ordinary chondrites found by J. A. Sanchez et al. (2020). The rectangular zone overlapping the S(IV) subtype represents the spectral zone for acapulcoite-lodranite clan meteorites found by M. P. Lucas et al. (2019). The rectangular zone (BA) includes the pyroxene-dominated basaltic achondrite assemblages. The dashed curve indicates the location of the olivine-orthopyroxene mixing line (E. A. Cloutis et al. 1986).