What Is Granite? ThoughtCo
#0183;#32;What Granite Means . Students of granites classify them in three or four categories. Itype (igneous) granites appear to arise from the melting of preexisting igneous rocks, Stype (sedimentary) granites from melted sedimentary rocks (or their metamorphic equivalents in both cases). Mtype (mantle) granites are rarer and are thought to have evolved directly from deeper melts in the mantle.