Solids. The lava in the vertical passage gets solidified. The next volcanic eruption through the pipe is accompanied by explosion of highly compressed gases throwing out block of solidified lava from inside the choked pipe. The solid material consists of fine ash and dust particles and angular fragments mostly of lava rock blow up from within the vent. If the diameter of the solid block thrown out by a volcano is more than 33 mm. it is known as volcanic bomb or blocks. At places volcanic bombs weighing 60 tons have seen but their number is small.