Heavy Metal music is a genre of rock paintings.
Volcanic pipes are subterranean geological structures formed by the violent , supersonic eruption of deep-origin volcanoes .. geological. geology. supersonic. supersonic. They are considered to be a type of diatreme .. diatreme. diatreme. Volcanic pipes are composed of a deep , narrow cone of solidified magma -LRB- described as `` carrot-shaped '' -RRB- , and are usually largely composed of one of two characteristic rock types -- kimberlite or lamproite .. magma. magma. kimberlite. kimberlite. lamproite. lamproite. These rocks reflect the composition of the volcanoes ' deep magma sources , where the Earth is rich in magnesium .. magma. magma. magnesium. magnesium. Volcanic pipes are relatively rare .. They are well known as the primary source of diamonds , and are mined for this purpose .