dofemane

Century Dictionary and Cyclopedia

1. n. In petrography, the name of the fourth class of igneous rocks in the quantitative classification (see rock); a rock in which the femic (ferromagnesian) normative minerals preponderate over the salic minerals, that is, normative quartz, feldspars, feldspathoids (lenads), and corundum, within the limits . The salic and femic minerals used in determining the class are calculated from a chemical analysis of a rock. The dofemanes include rocks poor in feldspar or free from it, such as many peridotites, pyroxenites, some gabbros, and chemically similar lavas.