Granitic pegmatites are sheet-like bodies of rock found in many areas of the earth's crust that have undergone episodes of mountain-building and the accompanying intrusion of granitic magmas into the upper crust. Most pegmatites are of simple mineralogical composition, and are composed soley quartz, feldspars, and micas. On rare occasions, some pegmatites become enriched in elements such as lithium, beryllium, boron, and fluorine, which results in a much more diverse and interesting suite of minerals.

A number of the minerals commonly found in these "complex" pegmatites are among some of the more popular and well-known gemstones today. These pegmatite gemstones include the aquamarine, morganite, and heliodor varieties of beryl, the multi=colored varieties of tourmaline, elbaite and liddicoatite, the gem variety of spodumene, kunzite, natural blue and sherry-colored topaz, and the spessartine variety of garnet.