The top of Mt. Cadillac is perfectly round like a dome. The rock began as molten magma that intruded into older, overlying rock. As it cooled, it hardened and crystallized. It is peppered with flecks of black horneblende and glistens with quartz crystal. Pink feldspar gives this granite its pink hue. Many rocks are also covered with multi-colored lichen which gives it a cheerful appearance.