3-Pegmatite dikes in granite

Dikes of course-grained (pegmatite) minerals in granite rock. Dike contains quartz (clear) and feldspar (pink) minerals. Rock crystallized beneath the surface, perhaps at a depth of several thousand feet. Granite crystallized first, then pegmatite dike intruded into it. Slow cooling of pegmatite magma allowed large crystals to form. (Compare with no. 4 and no. 5.)