The hydrothermal fluid from the deep crust gradually intruded and filled in along the fissures of granite. Under the appropriate environmental conditions such as depressurization, the mineral crystal in the hydrothermal fluid will form small-sized miarolitic cavities which are made of feldspar and quartz. . The flesh-coloured granule is feldspar crystal and the translucent granule is quartz crystal.

                                                           Feldspar and Quartz Crystal