Mount Pinatubo is a volcano on the island of Luzon in the  Philippines. It is best known for its enormous eruption on June 15,  1991.This eruption was the second largest of … the twentieth  century. 1 person found this useful.imilar to many other volcanoes it has a large assortment or rocks, a lot of granite as these rocks are carried out from the magma chamber. … There are other rocks such as basalt, Scoria, sandstone, mudstone, shale, limestone, quartize, hornfels, slate and marble. 4 people found this useful.