How to identify it?
Color
Pegmatite is mainly composed of white or gray quartz, and pink or white feldspar.
Texture
Crystal size is the most striking feature of pegmatites, with crystals usually over 2.5 cm in length. Pegmatite sometimes has a graphic texture - intimate intergrowth of alkali feldspar and quartz looks like ancient cuneiform writing when viewed in certain cross sections.
Photo By James St. John , used under CC-BY-2.0 /Cropped and compressed from original