伟晶岩形成于岩浆结晶分异的后期阶段,通常为富含挥发分的硅酸盐残浆侵入到岩浆岩或围岩裂隙中缓慢结晶而成。伟晶岩中的矿物颗粒较为粗大,常发育有其他岩石中所没有的稀有矿产。通常认为,较大的深度更有利于伟晶岩的生成。主要原因为:一是较大的深度可使热量散失缓慢,从而利于岩浆体系长时间结晶作用的进行;二是较大深度造就的高压条件使钾、钠 Pegmatite is formed in the late stage of differentiation of magma crystals. Usually, the residual volatile silicate mud intrudes into the magmatic rocks or slowly crystallizes in the surrounding rock cracks. Pegmatite mineral grains are more coarser, often with other rare rocks in the development of rare minerals. Generally believed that a greater depth is more conducive to the generation of pegmatite. The main reason is: First, the greater depth of heat loss can be slow, so as to facilitate the crystallization of the magma system for a long time to carry out; the second is the greater depth of the high-pressure conditions so that potassium, sodium